21621531062535 has 16 divisors (see below), whose sum is σ = 34594821141504. Its totient is φ = 11531359419552.

The previous prime is 21621531062513. The next prime is 21621531062569. The reversal of 21621531062535 is 53526013512612.

It is not a de Polignac number, because 21621531062535 - 2⁶ = 21621531062471 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6285967 + ... + 9097056.

It is an arithmetic number, because the mean of its divisors is an integer number (2162176321344).

Almost surely, 2^{21621531062535} is an apocalyptic number.

21621531062535 is a deficient number, since it is larger than the sum of its proper divisors (12973290078969).

21621531062535 is a wasteful number, since it uses less digits than its factorization.

21621531062535 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15476734.

The product of its (nonzero) digits is 324000, while the sum is 42.

The spelling of 21621531062535 in words is "twenty-one trillion, six hundred twenty-one billion, five hundred thirty-one million, sixty-two thousand, five hundred thirty-five".