64309440 has 112 divisors (see below), whose sum is σ = 219931488. Its totient is φ = 15826944.

The previous prime is 64309429. The next prime is 64309447. The reversal of 64309440 is 4490346.

It is a super-2 number, since 2×64309440² = 8271408146227200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 64309398 and 64309407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64309447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9904 + ... + 15056.

It is an arithmetic number, because the mean of its divisors is an integer number (1963674).

Almost surely, 2^64309440 is an apocalyptic number.

64309440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64309440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109965744).

64309440 is an abundant number, since it is smaller than the sum of its proper divisors (155622048).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

64309440 is a wasteful number, since it uses less digits than its factorization.

64309440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5186 (or 5176 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 30.

The square root of 64309440 is about 8019.3166791192. The cubic root of 64309440 is about 400.6436304608.

Adding to 64309440 its reverse (4490346), we get a palindrome (68799786).

The spelling of 64309440 in words is "sixty-four million, three hundred nine thousand, four hundred forty".