61661666011560 has 128 divisors (see below), whose sum is σ = 185063788800000. Its totient is φ = 16436109102336.

The previous prime is 61661666011559. The next prime is 61661666011609. The reversal of 61661666011560 is 6511066616616.

It is a super-2 number, since 2×61661666011560² (a number of 28 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3692528091 + ... + 3692544789.

It is an arithmetic number, because the mean of its divisors is an integer number (1445810850000).

Almost surely, 2^{61661666011560} is an apocalyptic number.

61661666011560 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

61661666011560 is an abundant number, since it is smaller than the sum of its proper divisors (123402122788440).

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

61661666011560 is a wasteful number, since it uses less digits than its factorization.

61661666011560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27975 (or 27971 counting only the distinct ones).

The product of its (nonzero) digits is 1399680, while the sum is 51.

The spelling of 61661666011560 in words is "sixty-one trillion, six hundred sixty-one billion, six hundred sixty-six million, eleven thousand, five hundred sixty".