31113100021 has 2 divisors, whose sum is σ = 31113100022. Its totient is φ = 31113100020.

The previous prime is 31113099973. The next prime is 31113100037. The reversal of 31113100021 is 12000131113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18147861796 + 12965238225 = 134714^2 + 113865^2 .

It is a cyclic number.

It is not a de Polignac number, because 31113100021 - 2¹⁹ = 31112575733 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31113099974 and 31113100010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31113100321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15556550010 + 15556550011.

It is an arithmetic number, because the mean of its divisors is an integer number (15556550011).

Almost surely, 2^31113100021 is an apocalyptic number.

It is an amenable number.

31113100021 is a deficient number, since it is larger than the sum of its proper divisors (1).

31113100021 is an equidigital number, since it uses as much as digits as its factorization.

31113100021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18, while the sum is 13.

Adding to 31113100021 its reverse (12000131113), we get a palindrome (43113231134).

The spelling of 31113100021 in words is "thirty-one billion, one hundred thirteen million, one hundred thousand, twenty-one".