21985902265 has 32 divisors (see below), whose sum is σ = 27112402944. Its totient is φ = 17110441920.

The previous prime is 21985902251. The next prime is 21985902271. The reversal of 21985902265 is 56220958912.

It is a de Polignac number, because none of the positive numbers 2^k-21985902265 is a prime.

It is a super-2 number, since 2×21985902265² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9960792 + ... + 9962998.

It is an arithmetic number, because the mean of its divisors is an integer number (847262592).

Almost surely, 2^21985902265 is an apocalyptic number.

It is an amenable number.

21985902265 is a deficient number, since it is larger than the sum of its proper divisors (5126500679).

21985902265 is a wasteful number, since it uses less digits than its factorization.

21985902265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2637.

The product of its (nonzero) digits is 777600, while the sum is 49.

The spelling of 21985902265 in words is "twenty-one billion, nine hundred eighty-five million, nine hundred two thousand, two hundred sixty-five".