21621960395 has 16 divisors (see below), whose sum is σ = 30155569920. Its totient is φ = 14575189344.

The previous prime is 21621960377. The next prime is 21621960403. The reversal of 21621960395 is 59306912612.

It is a cyclic number.

It is not a de Polignac number, because 21621960395 - 2²² = 21617766091 is a prime.

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 15 ways as a sum of consecutive naturals, for example, 5233277 + ... + 5237406.

It is an arithmetic number, because the mean of its divisors is an integer number (1884723120).

Almost surely, 2^21621960395 is an apocalyptic number.

21621960395 is a deficient number, since it is larger than the sum of its proper divisors (8533609525).

21621960395 is a wasteful number, since it uses less digits than its factorization.

21621960395 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10470754.

The product of its (nonzero) digits is 174960, while the sum is 44.

The spelling of 21621960395 in words is "twenty-one billion, six hundred twenty-one million, nine hundred sixty thousand, three hundred ninety-five".