64991960 has 32 divisors (see below), whose sum is σ = 159526800. Its totient is φ = 23633280.

The previous prime is 64991933. The next prime is 64991977. The reversal of 64991960 is 6919946.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 73415 + ... + 74294.

Almost surely, 2^64991960 is an apocalyptic number.

It is an amenable number.

64991960 is an abundant number, since it is smaller than the sum of its proper divisors (94534840).

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

64991960 is a wasteful number, since it uses less digits than its factorization.

64991960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147731 (or 147727 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 44.

The square root of 64991960 is about 8061.7591132457. The cubic root of 64991960 is about 402.0559974138.

The spelling of 64991960 in words is "sixty-four million, nine hundred ninety-one thousand, nine hundred sixty".