21615566102423 has 2 divisors, whose sum is σ = 21615566102424. Its totient is φ = 21615566102422.

The previous prime is 21615566102419. The next prime is 21615566102441. The reversal of 21615566102423 is 32420166551612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21615566102423 - 2² = 21615566102419 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21615566102413) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10807783051211 + 10807783051212.

It is an arithmetic number, because the mean of its divisors is an integer number (10807783051212).

Almost surely, 2^{21615566102423} is an apocalyptic number.

21615566102423 is a deficient number, since it is larger than the sum of its proper divisors (1).

21615566102423 is an equidigital number, since it uses as much as digits as its factorization.

21615566102423 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 518400, while the sum is 44.

The spelling of 21615566102423 in words is "twenty-one trillion, six hundred fifteen billion, five hundred sixty-six million, one hundred two thousand, four hundred twenty-three".