51661161566650 has 12 divisors (see below), whose sum is σ = 96089760514062. Its totient is φ = 20664464626640.

The previous prime is 51661161566617. The next prime is 51661161566653. The reversal of 51661161566650 is 5666516116615.

It can be written as a sum of positive squares in 3 ways, for example, as 19961210033209 + 31699951533441 = 4467797^2 + 5630271^2 .

It is a super-2 number, since 2×51661161566650² (a number of 28 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 51661161566591 and 51661161566600.

It is not an unprimeable number, because it can be changed into a prime (51661161566653) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 516611615617 + ... + 516611615716.

Almost surely, 2^{51661161566650} is an apocalyptic number.

51661161566650 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

51661161566650 is a deficient number, since it is larger than the sum of its proper divisors (44428598947412).

51661161566650 is a wasteful number, since it uses less digits than its factorization.

51661161566650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1033223231345 (or 1033223231340 counting only the distinct ones).

The product of its (nonzero) digits is 5832000, while the sum is 55.

The spelling of 51661161566650 in words is "fifty-one trillion, six hundred sixty-one billion, one hundred sixty-one million, five hundred sixty-six thousand, six hundred fifty".