31010111021 has 2 divisors, whose sum is σ = 31010111022. Its totient is φ = 31010111020.

The previous prime is 31010111003. The next prime is 31010111023. The reversal of 31010111021 is 12011101013.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17163882121 + 13846228900 = 131011^2 + 117670^2 .

It is a cyclic number.

It is not a de Polignac number, because 31010111021 - 2¹⁴ = 31010094637 is a prime.

Together with 31010111023, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 31010110993 and 31010111011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31010111023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15505055510 + 15505055511.

It is an arithmetic number, because the mean of its divisors is an integer number (15505055511).

Almost surely, 2^31010111021 is an apocalyptic number.

It is an amenable number.

31010111021 is a deficient number, since it is larger than the sum of its proper divisors (1).

31010111021 is an equidigital number, since it uses as much as digits as its factorization.

31010111021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6, while the sum is 11.

Adding to 31010111021 its reverse (12011101013), we get a palindrome (43021212034).

The spelling of 31010111021 in words is "thirty-one billion, ten million, one hundred eleven thousand, twenty-one".