21101512523 has 16 divisors (see below), whose sum is σ = 26027237376. Its totient is φ = 16659609120.

The previous prime is 21101512511. The next prime is 21101512529. The reversal of 21101512523 is 32521510112.

It is not a de Polignac number, because 21101512523 - 2¹⁴ = 21101496139 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21101512529) 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, 208283 + ... + 292548.

It is an arithmetic number, because the mean of its divisors is an integer number (1626702336).

Almost surely, 2^21101512523 is an apocalyptic number.

21101512523 is a deficient number, since it is larger than the sum of its proper divisors (4925724853).

21101512523 is a wasteful number, since it uses less digits than its factorization.

21101512523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 501314.

The product of its (nonzero) digits is 600, while the sum is 23.

The spelling of 21101512523 in words is "twenty-one billion, one hundred one million, five hundred twelve thousand, five hundred twenty-three".