15116505016621 has 2 divisors, whose sum is σ = 15116505016622. Its totient is φ = 15116505016620.

The previous prime is 15116505016603. The next prime is 15116505016637. The reversal of 15116505016621 is 12661050561151.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15116310720900 + 194295721 = 3887970^2 + 13939^2 .

It is a cyclic number.

It is not a de Polignac number, because 15116505016621 - 2³⁷ = 14979066063149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15116505016661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7558252508310 + 7558252508311.

It is an arithmetic number, because the mean of its divisors is an integer number (7558252508311).

Almost surely, 2^{15116505016621} is an apocalyptic number.

It is an amenable number.

15116505016621 is a deficient number, since it is larger than the sum of its proper divisors (1).

15116505016621 is an equidigital number, since it uses as much as digits as its factorization.

15116505016621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54000, while the sum is 40.

Adding to 15116505016621 its reverse (12661050561151), we get a palindrome (27777555577772).

The spelling of 15116505016621 in words is "fifteen trillion, one hundred sixteen billion, five hundred five million, sixteen thousand, six hundred twenty-one".