21105151823 has 24 divisors (see below), whose sum is σ = 25642143072. Its totient is φ = 17012934144.

The previous prime is 21105151751. The next prime is 21105151829. The reversal of 21105151823 is 32815150112.

It is not a de Polignac number, because 21105151823 - 2¹⁰ = 21105150799 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21105151829) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3308465 + ... + 3314837.

It is an arithmetic number, because the mean of its divisors is an integer number (1068422628).

Almost surely, 2^21105151823 is an apocalyptic number.

21105151823 is a deficient number, since it is larger than the sum of its proper divisors (4536991249).

21105151823 is a wasteful number, since it uses less digits than its factorization.

21105151823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8051 (or 8034 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 29.

The spelling of 21105151823 in words is "twenty-one billion, one hundred five million, one hundred fifty-one thousand, eight hundred twenty-three".