64391616 has 42 divisors (see below), whose sum is σ = 184568592. Its totient is φ = 21463680.

The previous prime is 64391603. The next prime is 64391633. The reversal of 64391616 is 61619346.

64391616 is a `hidden beast` number, since 6 + 4 + 39 + 1 + 616 = 666.

It is a super-2 number, since 2×64391616² = 8292560422182912, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 55320 + ... + 56471.

Almost surely, 2^64391616 is an apocalyptic number.

It is an amenable number.

64391616 is an abundant number, since it is smaller than the sum of its proper divisors (120176976).

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

64391616 is a wasteful number, since it uses less digits than its factorization.

64391616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111809 (or 111796 counting only the distinct ones).

The product of its digits is 23328, while the sum is 36.

The square root of 64391616 is about 8024.4386719571. The cubic root of 64391616 is about 400.8142082047.

The spelling of 64391616 in words is "sixty-four million, three hundred ninety-one thousand, six hundred sixteen".