21356147554031 has 4 divisors (see below), whose sum is σ = 21357269396232. Its totient is φ = 21355025711832.

The previous prime is 21356147553991. The next prime is 21356147554043. The reversal of 21356147554031 is 13045574165312.

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 21356147554031 - 2⁶ = 21356147553967 is a prime.

It is a super-2 number, since 2×21356147554031² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21356147554081) 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, 560892545 + ... + 560930618.

It is an arithmetic number, because the mean of its divisors is an integer number (5339317349058).

Almost surely, 2^{21356147554031} is an apocalyptic number.

21356147554031 is a deficient number, since it is larger than the sum of its proper divisors (1121842201).

21356147554031 is a wasteful number, since it uses less digits than its factorization.

21356147554031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1121842200.

The product of its (nonzero) digits is 1512000, while the sum is 47.

The spelling of 21356147554031 in words is "twenty-one trillion, three hundred fifty-six billion, one hundred forty-seven million, five hundred fifty-four thousand, thirty-one".