21615566102442 has 24 divisors (see below), whose sum is σ = 50436320906244. Its totient is φ = 6650943416064.

The previous prime is 21615566102441. The next prime is 21615566102453. The reversal of 21615566102442 is 24420166551612.

21615566102442 is a `hidden beast` number, since 2 + 1 + 6 + 1 + 5 + 5 + 6 + 610 + 24 + 4 + 2 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 18509191577361 + 3106374525081 = 4302231^2 + 1762491^2 .

It is not an unprimeable number, because it can be changed into a prime (21615566102441) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 46187106823 + ... + 46187107290.

Almost surely, 2^{21615566102442} is an apocalyptic number.

21615566102442 is an abundant number, since it is smaller than the sum of its proper divisors (28820754803802).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21615566102442 is a wasteful number, since it uses less digits than its factorization.

21615566102442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92374214134 (or 92374214131 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 45.

The spelling of 21615566102442 in words is "twenty-one trillion, six hundred fifteen billion, five hundred sixty-six million, one hundred two thousand, four hundred forty-two".