21353115523 has 4 divisors (see below), whose sum is σ = 22609181160. Its totient is φ = 20097049888.

The previous prime is 21353115493. The next prime is 21353115551. The reversal of 21353115523 is 32551135312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21353115523 - 2⁵ = 21353115491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21353115023) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 628032793 + ... + 628032826.

It is an arithmetic number, because the mean of its divisors is an integer number (5652295290).

Almost surely, 2^21353115523 is an apocalyptic number.

21353115523 is a deficient number, since it is larger than the sum of its proper divisors (1256065637).

21353115523 is a wasteful number, since it uses less digits than its factorization.

21353115523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1256065636.

The product of its digits is 13500, while the sum is 31.

The spelling of 21353115523 in words is "twenty-one billion, three hundred fifty-three million, one hundred fifteen thousand, five hundred twenty-three".