51505661677 has 2 divisors, whose sum is σ = 51505661678. Its totient is φ = 51505661676.

The previous prime is 51505661659. The next prime is 51505661687. The reversal of 51505661677 is 77616650515.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46234030441 + 5271631236 = 215021^2 + 72606^2 .

It is a cyclic number.

It is not a de Polignac number, because 51505661677 - 2³⁵ = 17145923309 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51505661677.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51505661687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25752830838 + 25752830839.

It is an arithmetic number, because the mean of its divisors is an integer number (25752830839).

Almost surely, 2^51505661677 is an apocalyptic number.

It is an amenable number.

51505661677 is a deficient number, since it is larger than the sum of its proper divisors (1).

51505661677 is an equidigital number, since it uses as much as digits as its factorization.

51505661677 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1323000, while the sum is 49.

The spelling of 51505661677 in words is "fifty-one billion, five hundred five million, six hundred sixty-one thousand, six hundred seventy-seven".