61518556761 has 64 divisors (see below), whose sum is σ = 89974748160. Its totient is φ = 37238538240.

The previous prime is 61518556753. The next prime is 61518556783. The reversal of 61518556761 is 16765581516.

It is not a de Polignac number, because 61518556761 - 2³ = 61518556753 is a prime.

It is a super-2 number, since 2×61518556761² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is not an unprimeable number, because it can be changed into a prime (61518556261) by changing a digit.

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 63 ways as a sum of consecutive naturals, for example, 62966305 + ... + 62967281.

It is an arithmetic number, because the mean of its divisors is an integer number (1405855440).

Almost surely, 2^61518556761 is an apocalyptic number.

It is an amenable number.

61518556761 is a deficient number, since it is larger than the sum of its proper divisors (28456191399).

61518556761 is a wasteful number, since it uses less digits than its factorization.

61518556761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1394.

The product of its digits is 1512000, while the sum is 51.

The spelling of 61518556761 in words is "sixty-one billion, five hundred eighteen million, five hundred fifty-six thousand, seven hundred sixty-one".