51660621487775 has 24 divisors (see below), whose sum is σ = 64423968008400. Its totient is φ = 41093221190400.

The previous prime is 51660621487751. The next prime is 51660621487841. The reversal of 51660621487775 is 57778412606615.

It is a happy number.

It is not a de Polignac number, because 51660621487775 - 2³⁰ = 51659547745951 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25912811 + ... + 27835139.

It is an arithmetic number, because the mean of its divisors is an integer number (2684332000350).

Almost surely, 2^{51660621487775} is an apocalyptic number.

51660621487775 is a deficient number, since it is larger than the sum of its proper divisors (12763346520625).

51660621487775 is a wasteful number, since it uses less digits than its factorization.

51660621487775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1928459 (or 1928454 counting only the distinct ones).

The product of its (nonzero) digits is 118540800, while the sum is 65.

The spelling of 51660621487775 in words is "fifty-one trillion, six hundred sixty billion, six hundred twenty-one million, four hundred eighty-seven thousand, seven hundred seventy-five".