231847331021 has 2 divisors, whose sum is σ = 231847331022. Its totient is φ = 231847331020.

The previous prime is 231847331003. The next prime is 231847331063. The reversal of 231847331021 is 120133748132.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 153511158025 + 78336172996 = 391805^2 + 279886^2 .

It is a cyclic number.

It is not a de Polignac number, because 231847331021 - 2¹⁴ = 231847314637 is a prime.

It is a super-2 number, since 2×231847331021² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231847331081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115923665510 + 115923665511.

It is an arithmetic number, because the mean of its divisors is an integer number (115923665511).

Almost surely, 2^231847331021 is an apocalyptic number.

It is an amenable number.

231847331021 is a deficient number, since it is larger than the sum of its proper divisors (1).

231847331021 is an equidigital number, since it uses as much as digits as its factorization.

231847331021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24192, while the sum is 35.

The spelling of 231847331021 in words is "two hundred thirty-one billion, eight hundred forty-seven million, three hundred thirty-one thousand, twenty-one".