21775251516631 has 2 divisors, whose sum is σ = 21775251516632. Its totient is φ = 21775251516630.

The previous prime is 21775251516541. The next prime is 21775251516703. The reversal of 21775251516631 is 13661515257712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21775251516631 - 2²⁷ = 21775117298903 is a prime.

It is a super-2 number, since 2×21775251516631² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21775251816631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10887625758315 + 10887625758316.

It is an arithmetic number, because the mean of its divisors is an integer number (10887625758316).

Almost surely, 2^{21775251516631} is an apocalyptic number.

21775251516631 is a deficient number, since it is larger than the sum of its proper divisors (1).

21775251516631 is an equidigital number, since it uses as much as digits as its factorization.

21775251516631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2646000, while the sum is 52.

The spelling of 21775251516631 in words is "twenty-one trillion, seven hundred seventy-five billion, two hundred fifty-one million, five hundred sixteen thousand, six hundred thirty-one".