64929920 has 128 divisors (see below), whose sum is σ = 177137280. Its totient is φ = 22528000.

The previous prime is 64929899. The next prime is 64929959. The reversal of 64929920 is 2992946.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×64929920² = 8431789022412800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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, 161720 + ... + 162120.

It is an arithmetic number, because the mean of its divisors is an integer number (1383885).

Almost surely, 2^64929920 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 64929920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88568640).

64929920 is an abundant number, since it is smaller than the sum of its proper divisors (112207360).

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

64929920 is a wasteful number, since it uses less digits than its factorization.

64929920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 454 (or 442 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 41.

The square root of 64929920 is about 8057.9103991047. The cubic root of 64929920 is about 401.9280251991.

The spelling of 64929920 in words is "sixty-four million, nine hundred twenty-nine thousand, nine hundred twenty".