31302031021 has 2 divisors, whose sum is σ = 31302031022. Its totient is φ = 31302031020.

The previous prime is 31302031009. The next prime is 31302031051. The reversal of 31302031021 is 12013020313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28289558025 + 3012472996 = 168195^2 + 54886^2 .

It is a cyclic number.

It is not a de Polignac number, because 31302031021 - 2¹¹ = 31302028973 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31302030986 and 31302031004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31302031051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15651015510 + 15651015511.

It is an arithmetic number, because the mean of its divisors is an integer number (15651015511).

Almost surely, 2^31302031021 is an apocalyptic number.

It is an amenable number.

31302031021 is a deficient number, since it is larger than the sum of its proper divisors (1).

31302031021 is an equidigital number, since it uses as much as digits as its factorization.

31302031021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108, while the sum is 16.

Adding to 31302031021 its reverse (12013020313), we get a palindrome (43315051334).

The spelling of 31302031021 in words is "thirty-one billion, three hundred two million, thirty-one thousand, twenty-one".