31232030021 has 2 divisors, whose sum is σ = 31232030022. Its totient is φ = 31232030020.

The previous prime is 31232029993. The next prime is 31232030023. The reversal of 31232030021 is 12003023213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31006279396 + 225750625 = 176086^2 + 15025^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31232030021 is a prime.

Together with 31232030023, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31232030023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15616015010 + 15616015011.

It is an arithmetic number, because the mean of its divisors is an integer number (15616015011).

Almost surely, 2^31232030021 is an apocalyptic number.

It is an amenable number.

31232030021 is a deficient number, since it is larger than the sum of its proper divisors (1).

31232030021 is an equidigital number, since it uses as much as digits as its factorization.

31232030021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 17.

Adding to 31232030021 its reverse (12003023213), we get a palindrome (43235053234).

The spelling of 31232030021 in words is "thirty-one billion, two hundred thirty-two million, thirty thousand, twenty-one".