21357177331 has 4 divisors (see below), whose sum is σ = 24408202672. Its totient is φ = 18306151992.

The previous prime is 21357177253. The next prime is 21357177341. The reversal of 21357177331 is 13377175312.

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 21357177331 - 2²⁷ = 21222959603 is a prime.

It is a super-2 number, since 2×21357177331² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21357177341) 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, 1525512660 + ... + 1525512673.

It is an arithmetic number, because the mean of its divisors is an integer number (6102050668).

Almost surely, 2^21357177331 is an apocalyptic number.

21357177331 is a deficient number, since it is larger than the sum of its proper divisors (3051025341).

21357177331 is an equidigital number, since it uses as much as digits as its factorization.

21357177331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3051025340.

The product of its digits is 92610, while the sum is 40.

The spelling of 21357177331 in words is "twenty-one billion, three hundred fifty-seven million, one hundred seventy-seven thousand, three hundred thirty-one".