21615100369 has 2 divisors, whose sum is σ = 21615100370. Its totient is φ = 21615100368.

The previous prime is 21615100307. The next prime is 21615100417. The reversal of 21615100369 is 96300151612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16560601344 + 5054499025 = 128688^2 + 71095^2 .

It is a cyclic number.

It is not a de Polignac number, because 21615100369 - 2¹⁵ = 21615067601 is a prime.

It is a super-2 number, since 2×21615100369² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21615100469) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10807550184 + 10807550185.

It is an arithmetic number, because the mean of its divisors is an integer number (10807550185).

Almost surely, 2^21615100369 is an apocalyptic number.

It is an amenable number.

21615100369 is a deficient number, since it is larger than the sum of its proper divisors (1).

21615100369 is an equidigital number, since it uses as much as digits as its factorization.

21615100369 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9720, while the sum is 34.

The spelling of 21615100369 in words is "twenty-one billion, six hundred fifteen million, one hundred thousand, three hundred sixty-nine".