64661625 has 192 divisors, whose sum is σ = 153653760. Its totient is φ = 26611200.

The previous prime is 64661621. The next prime is 64661657. The reversal of 64661625 is 52616646.

It is a happy number.

64661625 is a `hidden beast` number, since 646 + 6 + 1 + 6 + 2 + 5 = 666.

It is not a de Polignac number, because 64661625 - 2² = 64661621 is a prime.

It is a super-2 number, since 2×64661625² = 8362251495281250, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 64661625.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64661621) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 2811364 + ... + 2811386.

It is an arithmetic number, because the mean of its divisors is an integer number (800280).

Almost surely, 2^64661625 is an apocalyptic number.

It is an amenable number.

64661625 is an abundant number, since it is smaller than the sum of its proper divisors (88992135).

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

64661625 is a wasteful number, since it uses less digits than its factorization.

64661625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78 (or 55 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 64661625 is about 8041.2452393892. The cubic root of 64661625 is about 401.3736626440.

The spelling of 64661625 in words is "sixty-four million, six hundred sixty-one thousand, six hundred twenty-five".