31234043021 has 2 divisors, whose sum is σ = 31234043022. Its totient is φ = 31234043020.

The previous prime is 31234043003. The next prime is 31234043059. The reversal of 31234043021 is 12034043213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31192504996 + 41538025 = 176614^2 + 6445^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31234043021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31234043821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15617021510 + 15617021511.

It is an arithmetic number, because the mean of its divisors is an integer number (15617021511).

Almost surely, 2^31234043021 is an apocalyptic number.

It is an amenable number.

31234043021 is a deficient number, since it is larger than the sum of its proper divisors (1).

31234043021 is an equidigital number, since it uses as much as digits as its factorization.

31234043021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 23.

Adding to 31234043021 its reverse (12034043213), we get a palindrome (43268086234).

The spelling of 31234043021 in words is "thirty-one billion, two hundred thirty-four million, forty-three thousand, twenty-one".