64669520 has 20 divisors (see below), whose sum is σ = 150356820. Its totient is φ = 25867776.

The previous prime is 64669519. The next prime is 64669523. The reversal of 64669520 is 2596646.

It can be written as a sum of positive squares in 2 ways, for example, as 10086976 + 54582544 = 3176^2 + 7388^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64669523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 404105 + ... + 404264.

It is an arithmetic number, because the mean of its divisors is an integer number (7517841).

Almost surely, 2^64669520 is an apocalyptic number.

It is an amenable number.

64669520 is an abundant number, since it is smaller than the sum of its proper divisors (85687300).

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

64669520 is a wasteful number, since it uses less digits than its factorization.

64669520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 808382 (or 808376 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 38.

The square root of 64669520 is about 8041.7361309608. The cubic root of 64669520 is about 401.3899975057.

The spelling of 64669520 in words is "sixty-four million, six hundred sixty-nine thousand, five hundred twenty".