21515410554231 has 32 divisors (see below), whose sum is σ = 33163950175488. Its totient is φ = 12262265392640.

The previous prime is 21515410554223. The next prime is 21515410554241. The reversal of 21515410554231 is 13245501451512.

It is a cyclic number.

It is not a de Polignac number, because 21515410554231 - 2³ = 21515410554223 is a prime.

It is a super-2 number, since 2×21515410554231² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21515410554231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21515410554241) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15489060 + ... + 16820873.

It is an arithmetic number, because the mean of its divisors is an integer number (1036373442984).

Almost surely, 2^{21515410554231} is an apocalyptic number.

21515410554231 is a deficient number, since it is larger than the sum of its proper divisors (11648539621257).

21515410554231 is a wasteful number, since it uses less digits than its factorization.

21515410554231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32311151.

The product of its (nonzero) digits is 120000, while the sum is 39.

The spelling of 21515410554231 in words is "twenty-one trillion, five hundred fifteen billion, four hundred ten million, five hundred fifty-four thousand, two hundred thirty-one".