31374272221 has 2 divisors, whose sum is σ = 31374272222. Its totient is φ = 31374272220.

The previous prime is 31374272219. The next prime is 31374272227. The reversal of 31374272221 is 12227247313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18771740100 + 12602532121 = 137010^2 + 112261^2 .

It is an emirp because it is prime and its reverse (12227247313) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31374272221 - 2¹ = 31374272219 is a prime.

Together with 31374272219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31374272227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15687136110 + 15687136111.

It is an arithmetic number, because the mean of its divisors is an integer number (15687136111).

Almost surely, 2^31374272221 is an apocalyptic number.

It is an amenable number.

31374272221 is a deficient number, since it is larger than the sum of its proper divisors (1).

31374272221 is an equidigital number, since it uses as much as digits as its factorization.

31374272221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 28224, while the sum is 34.

The spelling of 31374272221 in words is "thirty-one billion, three hundred seventy-four million, two hundred seventy-two thousand, two hundred twenty-one".