21177747037 has 2 divisors, whose sum is σ = 21177747038. Its totient is φ = 21177747036.

The previous prime is 21177747011. The next prime is 21177747043. The reversal of 21177747037 is 73074777112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21033410841 + 144336196 = 145029^2 + 12014^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21177747037 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21177747067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10588873518 + 10588873519.

It is an arithmetic number, because the mean of its divisors is an integer number (10588873519).

Almost surely, 2^21177747037 is an apocalyptic number.

It is an amenable number.

21177747037 is a deficient number, since it is larger than the sum of its proper divisors (1).

21177747037 is an equidigital number, since it uses as much as digits as its factorization.

21177747037 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 403368, while the sum is 46.

The spelling of 21177747037 in words is "twenty-one billion, one hundred seventy-seven million, seven hundred forty-seven thousand, thirty-seven".