21615566102453 has 2 divisors, whose sum is σ = 21615566102454. Its totient is φ = 21615566102452.

The previous prime is 21615566102441. The next prime is 21615566102479. The reversal of 21615566102453 is 35420166551612.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21510283374724 + 105282727729 = 4637918^2 + 324473^2 .

It is a cyclic number.

It is not a de Polignac number, because 21615566102453 - 2⁸ = 21615566102197 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21615566102398 and 21615566102407.

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, 10807783051226 + 10807783051227.

It is an arithmetic number, because the mean of its divisors is an integer number (10807783051227).

Almost surely, 2^{21615566102453} is an apocalyptic number.

It is an amenable number.

21615566102453 is a deficient number, since it is larger than the sum of its proper divisors (1).

21615566102453 is an equidigital number, since it uses as much as digits as its factorization.

21615566102453 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296000, while the sum is 47.

The spelling of 21615566102453 in words is "twenty-one trillion, six hundred fifteen billion, five hundred sixty-six million, one hundred two thousand, four hundred fifty-three".