21469872691 has 2 divisors, whose sum is σ = 21469872692. Its totient is φ = 21469872690.

The previous prime is 21469872659. The next prime is 21469872701. The reversal of 21469872691 is 19627896412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21469872691 - 2⁵ = 21469872659 is a prime.

It is not a weakly prime, because it can be changed into another prime (21469872601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10734936345 + 10734936346.

It is an arithmetic number, because the mean of its divisors is an integer number (10734936346).

Almost surely, 2^21469872691 is an apocalyptic number.

21469872691 is a deficient number, since it is larger than the sum of its proper divisors (1).

21469872691 is an equidigital number, since it uses as much as digits as its factorization.

21469872691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2612736, while the sum is 55.

The spelling of 21469872691 in words is "twenty-one billion, four hundred sixty-nine million, eight hundred seventy-two thousand, six hundred ninety-one".