61666475689578 has 96 divisors (see below), whose sum is σ = 131260355573760. Its totient is φ = 19310555988000.

The previous prime is 61666475689549. The next prime is 61666475689589. The reversal of 61666475689578 is 87598657466616.

It is a self number, because there is not a number n which added to its sum of digits gives 61666475689578.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 123162343 + ... + 123662021.

It is an arithmetic number, because the mean of its divisors is an integer number (1367295370560).

Almost surely, 2^{61666475689578} is an apocalyptic number.

61666475689578 is an abundant number, since it is smaller than the sum of its proper divisors (69593879884182).

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

61666475689578 is a wasteful number, since it uses less digits than its factorization.

61666475689578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 500200 (or 500181 counting only the distinct ones).

The product of its digits is 21946982400, while the sum is 84.

The spelling of 61666475689578 in words is "sixty-one trillion, six hundred sixty-six billion, four hundred seventy-five million, six hundred eighty-nine thousand, five hundred seventy-eight".