51550506500661 has 80 divisors (see below), whose sum is σ = 94308322356864. Its totient is φ = 27390609893376.

The previous prime is 51550506500657. The next prime is 51550506500677. The reversal of 51550506500661 is 16600560505515.

It is not a de Polignac number, because 51550506500661 - 2² = 51550506500657 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51550506500161) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 31417540 + ... + 33017613.

Almost surely, 2^{51550506500661} is an apocalyptic number.

51550506500661 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

It is an amenable number.

51550506500661 is a deficient number, since it is larger than the sum of its proper divisors (42757815856203).

51550506500661 is a wasteful number, since it uses less digits than its factorization.

51550506500661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64435272 (or 64435263 counting only the distinct ones).

The product of its (nonzero) digits is 675000, while the sum is 45.

The spelling of 51550506500661 in words is "fifty-one trillion, five hundred fifty billion, five hundred six million, five hundred thousand, six hundred sixty-one".