21615566102441 has 2 divisors, whose sum is σ = 21615566102442. Its totient is φ = 21615566102440.

The previous prime is 21615566102423. The next prime is 21615566102453. The reversal of 21615566102441 is 14420166551612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21613005742441 + 2560360000 = 4648979^2 + 50600^2 .

It is a cyclic number.

It is not a de Polignac number, because 21615566102441 - 2²⁶ = 21615498993577 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21615566102392 and 21615566102401.

It is not a weakly prime, because it can be changed into another prime (21615569102441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10807783051220 + 10807783051221.

It is an arithmetic number, because the mean of its divisors is an integer number (10807783051221).

Almost surely, 2^{21615566102441} is an apocalyptic number.

It is an amenable number.

21615566102441 is a deficient number, since it is larger than the sum of its proper divisors (1).

21615566102441 is an equidigital number, since it uses as much as digits as its factorization.

21615566102441 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 345600, while the sum is 44.

The spelling of 21615566102441 in words is "twenty-one trillion, six hundred fifteen billion, five hundred sixty-six million, one hundred two thousand, four hundred forty-one".