21903964931 has 2 divisors, whose sum is σ = 21903964932. Its totient is φ = 21903964930.

The previous prime is 21903964879. The next prime is 21903964987. The reversal of 21903964931 is 13946930912.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21903964931 - 2⁶ = 21903964867 is a prime.

It is a super-2 number, since 2×21903964931² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21903964991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10951982465 + 10951982466.

It is an arithmetic number, because the mean of its divisors is an integer number (10951982466).

Almost surely, 2^21903964931 is an apocalyptic number.

21903964931 is a deficient number, since it is larger than the sum of its proper divisors (1).

21903964931 is an equidigital number, since it uses as much as digits as its factorization.

21903964931 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 314928, while the sum is 47.

The spelling of 21903964931 in words is "twenty-one billion, nine hundred three million, nine hundred sixty-four thousand, nine hundred thirty-one".