61655720136 has 16 divisors (see below), whose sum is σ = 154139300400. Its totient is φ = 20551906704.

The previous prime is 61655720129. The next prime is 61655720141. The reversal of 61655720136 is 63102755616.

It is a super-3 number, since 3×61655720136³ (a number of 33 digits) contains 333 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1284494146 + ... + 1284494193.

It is an arithmetic number, because the mean of its divisors is an integer number (9633706275).

Almost surely, 2^61655720136 is an apocalyptic number.

It is an amenable number.

61655720136 is an abundant number, since it is smaller than the sum of its proper divisors (92483580264).

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

61655720136 is a wasteful number, since it uses less digits than its factorization.

61655720136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2568988348 (or 2568988344 counting only the distinct ones).

The product of its (nonzero) digits is 226800, while the sum is 42.

The spelling of 61655720136 in words is "sixty-one billion, six hundred fifty-five million, seven hundred twenty thousand, one hundred thirty-six".