61565664 has 48 divisors (see below), whose sum is σ = 168642432. Its totient is φ = 19628928.

The previous prime is 61565657. The next prime is 61565711. The reversal of 61565664 is 46656516.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11734 + ... + 16149.

It is an arithmetic number, because the mean of its divisors is an integer number (3513384).

Almost surely, 2^61565664 is an apocalyptic number.

It is an amenable number.

61565664 is an abundant number, since it is smaller than the sum of its proper divisors (107076768).

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

61565664 is a wasteful number, since it uses less digits than its factorization.

61565664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27919 (or 27911 counting only the distinct ones).

The product of its digits is 129600, while the sum is 39.

The square root of 61565664 is about 7846.3790374924. The cubic root of 61565664 is about 394.8627713230.

The spelling of 61565664 in words is "sixty-one million, five hundred sixty-five thousand, six hundred sixty-four".