21131534123 has 32 divisors (see below), whose sum is σ = 26608103424. Its totient is φ = 16369546752.

The previous prime is 21131534101. The next prime is 21131534131. The reversal of 21131534123 is 32143513112.

It is a cyclic number.

It is not a de Polignac number, because 21131534123 - 2¹⁰ = 21131533099 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21131534092 and 21131534101.

It is not an unprimeable number, because it can be changed into a prime (21131534143) 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, 260786 + ... + 332072.

It is an arithmetic number, because the mean of its divisors is an integer number (831503232).

Almost surely, 2^21131534123 is an apocalyptic number.

21131534123 is a deficient number, since it is larger than the sum of its proper divisors (5476569301).

21131534123 is a wasteful number, since it uses less digits than its factorization.

21131534123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71411.

The product of its digits is 2160, while the sum is 26.

The spelling of 21131534123 in words is "twenty-one billion, one hundred thirty-one million, five hundred thirty-four thousand, one hundred twenty-three".