61591814664 has 64 divisors (see below), whose sum is σ = 163116292800. Its totient is φ = 19326138624.

The previous prime is 61591814659. The next prime is 61591814677. The reversal of 61591814664 is 46641819516.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 358567 + ... + 501750.

It is an arithmetic number, because the mean of its divisors is an integer number (2548692075).

Almost surely, 2^61591814664 is an apocalyptic number.

It is an amenable number.

61591814664 is an abundant number, since it is smaller than the sum of its proper divisors (101524478136).

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

61591814664 is a wasteful number, since it uses less digits than its factorization.

61591814664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 860502 (or 860498 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 51.

The spelling of 61591814664 in words is "sixty-one billion, five hundred ninety-one million, eight hundred fourteen thousand, six hundred sixty-four".