664774440 has 128 divisors (see below), whose sum is σ = 2183932800. Its totient is φ = 160542720.

The previous prime is 664774433. The next prime is 664774441. The reversal of 664774440 is 44477466.

It is a junction number, because it is equal to n+sod(n) for n = 664774392 and 664774401.

It is not an unprimeable number, because it can be changed into a prime (664774441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 412356 + ... + 413964.

It is an arithmetic number, because the mean of its divisors is an integer number (17061975).

Almost surely, 2^664774440 is an apocalyptic number.

664774440 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 664774440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1091966400).

664774440 is an abundant number, since it is smaller than the sum of its proper divisors (1519158360).

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

664774440 is a wasteful number, since it uses less digits than its factorization.

664774440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1947 (or 1943 counting only the distinct ones).

The product of its (nonzero) digits is 451584, while the sum is 42.

The square root of 664774440 is about 25783.2201247245. The cubic root of 664774440 is about 872.7531754070.

The spelling of 664774440 in words is "six hundred sixty-four million, seven hundred seventy-four thousand, four hundred forty".