61777987776 has 84 divisors (see below), whose sum is σ = 178203577552. Its totient is φ = 20461469184.

The previous prime is 61777987763. The next prime is 61777987781. The reversal of 61777987776 is 67778977716.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 251140 + ... + 432003.

Almost surely, 2^61777987776 is an apocalyptic number.

It is an amenable number.

61777987776 is an abundant number, since it is smaller than the sum of its proper divisors (116425589776).

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

61777987776 is a wasteful number, since it uses less digits than its factorization.

61777987776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 683318 (or 683305 counting only the distinct ones).

The product of its digits is 304946208, while the sum is 72.

The spelling of 61777987776 in words is "sixty-one billion, seven hundred seventy-seven million, nine hundred eighty-seven thousand, seven hundred seventy-six".