231040000021 has 4 divisors (see below), whose sum is σ = 231041830572. Its totient is φ = 231038169472.

The previous prime is 231039999989. The next prime is 231040000043. The reversal of 231040000021 is 120000040132.

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 101688280996 + 129351719025 = 318886^2 + 359655^2 .

It is a cyclic number.

It is not a de Polignac number, because 231040000021 - 2⁵ = 231039999989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 231039999956 and 231040000010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231040000421) 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, 710716 + ... + 983461.

It is an arithmetic number, because the mean of its divisors is an integer number (57760457643).

Almost surely, 2^231040000021 is an apocalyptic number.

It is an amenable number.

231040000021 is a deficient number, since it is larger than the sum of its proper divisors (1830551).

231040000021 is a wasteful number, since it uses less digits than its factorization.

231040000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1830550.

The product of its (nonzero) digits is 48, while the sum is 13.

Adding to 231040000021 its reverse (120000040132), we get a palindrome (351040040153).

The spelling of 231040000021 in words is "two hundred thirty-one billion, forty million, twenty-one", and thus it is an aban number.