31402130021 has 2 divisors, whose sum is σ = 31402130022. Its totient is φ = 31402130020.

The previous prime is 31402129981. The next prime is 31402130027. The reversal of 31402130021 is 12003120413.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22428357121 + 8973772900 = 149761^2 + 94730^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31402130021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31402130027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15701065010 + 15701065011.

It is an arithmetic number, because the mean of its divisors is an integer number (15701065011).

Almost surely, 2^31402130021 is an apocalyptic number.

It is an amenable number.

31402130021 is a deficient number, since it is larger than the sum of its proper divisors (1).

31402130021 is an equidigital number, since it uses as much as digits as its factorization.

31402130021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 31402130021 its reverse (12003120413), we get a palindrome (43405250434).

The spelling of 31402130021 in words is "thirty-one billion, four hundred two million, one hundred thirty thousand, twenty-one".