21517265630 has 24 divisors (see below), whose sum is σ = 45054520488. Its totient is φ = 7377348048.

The previous prime is 21517265611. The next prime is 21517265641. The reversal of 21517265630 is 3656271512.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21955904 + ... + 21956883.

It is an arithmetic number, because the mean of its divisors is an integer number (1877271687).

Almost surely, 2^21517265630 is an apocalyptic number.

21517265630 is an abundant number, since it is smaller than the sum of its proper divisors (23537254858).

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

21517265630 is a wasteful number, since it uses less digits than its factorization.

21517265630 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43912808 (or 43912801 counting only the distinct ones).

The product of its (nonzero) digits is 75600, while the sum is 38.

The spelling of 21517265630 in words is "twenty-one billion, five hundred seventeen million, two hundred sixty-five thousand, six hundred thirty".