21356374523 has 6 divisors (see below), whose sum is σ = 23474362212. Its totient is φ = 19414885820.

The previous prime is 21356374519. The next prime is 21356374591. The reversal of 21356374523 is 32547365312.

It is not a de Polignac number, because 21356374523 - 2² = 21356374519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21356374513) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 88249361 + ... + 88249602.

It is an arithmetic number, because the mean of its divisors is an integer number (3912393702).

Almost surely, 2^21356374523 is an apocalyptic number.

21356374523 is a deficient number, since it is larger than the sum of its proper divisors (2117987689).

21356374523 is a wasteful number, since it uses less digits than its factorization.

21356374523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176498985 (or 176498974 counting only the distinct ones).

The product of its digits is 453600, while the sum is 41.

The spelling of 21356374523 in words is "twenty-one billion, three hundred fifty-six million, three hundred seventy-four thousand, five hundred twenty-three".