64691928 has 96 divisors (see below), whose sum is σ = 204572160. Its totient is φ = 18083520.

The previous prime is 64691927. The next prime is 64691969. The reversal of 64691928 is 82919646.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64691927) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22323 + ... + 25053.

It is an arithmetic number, because the mean of its divisors is an integer number (2130960).

Almost surely, 2^64691928 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 64691928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102286080).

64691928 is an abundant number, since it is smaller than the sum of its proper divisors (139880232).

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

64691928 is a wasteful number, since it uses less digits than its factorization.

64691928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2797 (or 2790 counting only the distinct ones).

The product of its digits is 186624, while the sum is 45.

The square root of 64691928 is about 8043.1292417815. The cubic root of 64691928 is about 401.4363527202.

The spelling of 64691928 in words is "sixty-four million, six hundred ninety-one thousand, nine hundred twenty-eight".