64915240 has 64 divisors (see below), whose sum is σ = 162408960. Its totient is φ = 23189760.

The previous prime is 64915237. The next prime is 64915241. The reversal of 64915240 is 4251946.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is not an unprimeable number, because it can be changed into a prime (64915241) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14107 + ... + 18133.

It is an arithmetic number, because the mean of its divisors is an integer number (2537640).

Almost surely, 2^64915240 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64915240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81204480).

64915240 is an abundant number, since it is smaller than the sum of its proper divisors (97493720).

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

64915240 is a wasteful number, since it uses less digits than its factorization.

64915240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4082 (or 4078 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 64915240 is about 8056.9994414794. Note that the first 3 decimals coincide. The cubic root of 64915240 is about 401.8977322919.

The spelling of 64915240 in words is "sixty-four million, nine hundred fifteen thousand, two hundred forty".