21630521523 has 16 divisors (see below), whose sum is σ = 32886223776. Its totient is φ = 12528084480.

The previous prime is 21630521461. The next prime is 21630521551. The reversal of 21630521523 is 32512503612.

It is not a de Polignac number, because 21630521523 - 2¹⁷ = 21630390451 is a prime.

It is a super-2 number, since 2×21630521523² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21630521323) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16311948 + ... + 16313273.

It is an arithmetic number, because the mean of its divisors is an integer number (2055388986).

Almost surely, 2^21630521523 is an apocalyptic number.

21630521523 is a deficient number, since it is larger than the sum of its proper divisors (11255702253).

21630521523 is a wasteful number, since it uses less digits than its factorization.

21630521523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32625254.

The product of its (nonzero) digits is 10800, while the sum is 30.

The spelling of 21630521523 in words is "twenty-one billion, six hundred thirty million, five hundred twenty-one thousand, five hundred twenty-three".