61778615136 has 72 divisors (see below), whose sum is σ = 188645428440. Its totient is φ = 17651031552.

The previous prime is 61778615123. The next prime is 61778615141. The reversal of 61778615136 is 63151687716.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6561901 + ... + 6571308.

It is an arithmetic number, because the mean of its divisors is an integer number (2620075395).

Almost surely, 2^61778615136 is an apocalyptic number.

It is an amenable number.

61778615136 is an abundant number, since it is smaller than the sum of its proper divisors (126866813304).

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

61778615136 is a wasteful number, since it uses less digits than its factorization.

61778615136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13133236 (or 13133221 counting only the distinct ones).

The product of its digits is 1270080, while the sum is 51.

The spelling of 61778615136 in words is "sixty-one billion, seven hundred seventy-eight million, six hundred fifteen thousand, one hundred thirty-six".