21507535656023 has 8 divisors (see below), whose sum is σ = 21546898508448. Its totient is φ = 21468175491744.

The previous prime is 21507535656007. The next prime is 21507535656071. The reversal of 21507535656023 is 32065653570512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21507535656023 - 2⁴ = 21507535656007 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21507535256023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15709265 + ... + 17023397.

It is an arithmetic number, because the mean of its divisors is an integer number (2693362313556).

Almost surely, 2^{21507535656023} is an apocalyptic number.

21507535656023 is a deficient number, since it is larger than the sum of its proper divisors (39362852425).

21507535656023 is a wasteful number, since it uses less digits than its factorization.

21507535656023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1344073.

The product of its (nonzero) digits is 5670000, while the sum is 50.

The spelling of 21507535656023 in words is "twenty-one trillion, five hundred seven billion, five hundred thirty-five million, six hundred fifty-six thousand, twenty-three".