21278632831 has 2 divisors, whose sum is σ = 21278632832. Its totient is φ = 21278632830.

The previous prime is 21278632747. The next prime is 21278632871. The reversal of 21278632831 is 13823687212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21278632831 - 2¹⁹ = 21278108543 is a prime.

It is a super-2 number, since 2×21278632831² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21278632871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10639316415 + 10639316416.

It is an arithmetic number, because the mean of its divisors is an integer number (10639316416).

Almost surely, 2^21278632831 is an apocalyptic number.

21278632831 is a deficient number, since it is larger than the sum of its proper divisors (1).

21278632831 is an equidigital number, since it uses as much as digits as its factorization.

21278632831 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 193536, while the sum is 43.

The spelling of 21278632831 in words is "twenty-one billion, two hundred seventy-eight million, six hundred thirty-two thousand, eight hundred thirty-one".