31241243021 has 2 divisors, whose sum is σ = 31241243022. Its totient is φ = 31241243020.

The previous prime is 31241242979. The next prime is 31241243041. The reversal of 31241243021 is 12034214213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30738855625 + 502387396 = 175325^2 + 22414^2 .

It is a cyclic number.

It is not a de Polignac number, because 31241243021 - 2⁶ = 31241242957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31241243041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15620621510 + 15620621511.

It is an arithmetic number, because the mean of its divisors is an integer number (15620621511).

Almost surely, 2^31241243021 is an apocalyptic number.

It is an amenable number.

31241243021 is a deficient number, since it is larger than the sum of its proper divisors (1).

31241243021 is an equidigital number, since it uses as much as digits as its factorization.

31241243021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 23.

Adding to 31241243021 its reverse (12034214213), we get a palindrome (43275457234).

The spelling of 31241243021 in words is "thirty-one billion, two hundred forty-one million, two hundred forty-three thousand, twenty-one".