61644664 has 64 divisors (see below), whose sum is σ = 127360800. Its totient is φ = 27869184.

The previous prime is 61644617. The next prime is 61644697. The reversal of 61644664 is 46644616.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 545472 + ... + 545584.

Almost surely, 2^61644664 is an apocalyptic number.

It is an amenable number.

61644664 is an abundant number, since it is smaller than the sum of its proper divisors (65716136).

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

61644664 is a wasteful number, since it uses less digits than its factorization.

61644664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272 (or 268 counting only the distinct ones).

The product of its digits is 82944, while the sum is 37.

The square root of 61644664 is about 7851.4115928284. The cubic root of 61644664 is about 395.0315928371.

The spelling of 61644664 in words is "sixty-one million, six hundred forty-four thousand, six hundred sixty-four".