21331131023 has 4 divisors (see below), whose sum is σ = 21519902208. Its totient is φ = 21142359840.

The previous prime is 21331131011. The next prime is 21331131037. The reversal of 21331131023 is 32013113312.

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 21331131023 - 2⁴ = 21331131007 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21331130986 and 21331131004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21331131083) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 94385423 + ... + 94385648.

It is an arithmetic number, because the mean of its divisors is an integer number (5379975552).

Almost surely, 2^21331131023 is an apocalyptic number.

21331131023 is a deficient number, since it is larger than the sum of its proper divisors (188771185).

21331131023 is a wasteful number, since it uses less digits than its factorization.

21331131023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188771184.

The product of its (nonzero) digits is 324, while the sum is 20.

Adding to 21331131023 its reverse (32013113312), we get a palindrome (53344244335).

The spelling of 21331131023 in words is "twenty-one billion, three hundred thirty-one million, one hundred thirty-one thousand, twenty-three".