21312010277 has 2 divisors, whose sum is σ = 21312010278. Its totient is φ = 21312010276.

The previous prime is 21312010219. The next prime is 21312010297. The reversal of 21312010277 is 77201021312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14631563521 + 6680446756 = 120961^2 + 81734^2 .

It is a cyclic number.

It is not a de Polignac number, because 21312010277 - 2⁸ = 21312010021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21312010297) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10656005138 + 10656005139.

It is an arithmetic number, because the mean of its divisors is an integer number (10656005139).

Almost surely, 2^21312010277 is an apocalyptic number.

It is an amenable number.

21312010277 is a deficient number, since it is larger than the sum of its proper divisors (1).

21312010277 is an equidigital number, since it uses as much as digits as its factorization.

21312010277 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1176, while the sum is 26.

Adding to 21312010277 its reverse (77201021312), we get a palindrome (98513031589).

The spelling of 21312010277 in words is "twenty-one billion, three hundred twelve million, ten thousand, two hundred seventy-seven".