21466919231 has 2 divisors, whose sum is σ = 21466919232. Its totient is φ = 21466919230.

The previous prime is 21466919219. The next prime is 21466919239. The reversal of 21466919231 is 13291966412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21466919231 - 2¹⁸ = 21466657087 is a prime.

It is a super-2 number, since 2×21466919231² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21466919239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10733459615 + 10733459616.

It is an arithmetic number, because the mean of its divisors is an integer number (10733459616).

Almost surely, 2^21466919231 is an apocalyptic number.

21466919231 is a deficient number, since it is larger than the sum of its proper divisors (1).

21466919231 is an equidigital number, since it uses as much as digits as its factorization.

21466919231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 139968, while the sum is 44.

The spelling of 21466919231 in words is "twenty-one billion, four hundred sixty-six million, nine hundred nineteen thousand, two hundred thirty-one".