23131120021 has 4 divisors (see below), whose sum is σ = 23131452652. Its totient is φ = 23130787392.

The previous prime is 23131120013. The next prime is 23131120027. The reversal of 23131120021 is 12002113132.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3204692100 + 19926427921 = 56610^2 + 141161^2 .

It is a cyclic number.

It is not a de Polignac number, because 23131120021 - 2³ = 23131120013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 23131119977 and 23131120004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23131120027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17796 + ... + 215821.

It is an arithmetic number, because the mean of its divisors is an integer number (5782863163).

Almost surely, 2^23131120021 is an apocalyptic number.

It is an amenable number.

23131120021 is a deficient number, since it is larger than the sum of its proper divisors (332631).

23131120021 is an equidigital number, since it uses as much as digits as its factorization.

23131120021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332630.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 23131120021 its reverse (12002113132), we get a palindrome (35133233153).

The spelling of 23131120021 in words is "twenty-three billion, one hundred thirty-one million, one hundred twenty thousand, twenty-one".