231240404021 has 4 divisors (see below), whose sum is σ = 252262258944. Its totient is φ = 210218549100.

The previous prime is 231240404009. The next prime is 231240404081. The reversal of 231240404021 is 120404042132.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 231240404021 - 2²² = 231236209717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231240404081) 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, 10510927445 + ... + 10510927466.

It is an arithmetic number, because the mean of its divisors is an integer number (63065564736).

Almost surely, 2^231240404021 is an apocalyptic number.

It is an amenable number.

231240404021 is a deficient number, since it is larger than the sum of its proper divisors (21021854923).

231240404021 is a wasteful number, since it uses less digits than its factorization.

231240404021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21021854922.

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 231240404021 its reverse (120404042132), we get a palindrome (351644446153).

The spelling of 231240404021 in words is "two hundred thirty-one billion, two hundred forty million, four hundred four thousand, twenty-one".