65391928 has 64 divisors (see below), whose sum is σ = 149688000. Its totient is φ = 26142720.

The previous prime is 65391917. The next prime is 65391929. The reversal of 65391928 is 82919356.

It is a happy number.

It is a super-2 number, since 2×65391928² = 8552208495114368, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65391929) 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, 141618 + ... + 142078.

It is an arithmetic number, because the mean of its divisors is an integer number (2338875).

Almost surely, 2^65391928 is an apocalyptic number.

65391928 is a gapful number since it is divisible by the number (68) 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 65391928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74844000).

65391928 is an abundant number, since it is smaller than the sum of its proper divisors (84296072).

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

65391928 is a wasteful number, since it uses less digits than its factorization.

65391928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 640 (or 636 counting only the distinct ones).

The product of its digits is 116640, while the sum is 43.

The square root of 65391928 is about 8086.5275613207. The cubic root of 65391928 is about 402.8790775624.

The spelling of 65391928 in words is "sixty-five million, three hundred ninety-one thousand, nine hundred twenty-eight".