31221225457 has 2 divisors, whose sum is σ = 31221225458. Its totient is φ = 31221225456.

The previous prime is 31221225439. The next prime is 31221225479. The reversal of 31221225457 is 75452212213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26814390001 + 4406835456 = 163751^2 + 66384^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31221225457 is a prime.

It is not a weakly prime, because it can be changed into another prime (31221225557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15610612728 + 15610612729.

It is an arithmetic number, because the mean of its divisors is an integer number (15610612729).

Almost surely, 2^31221225457 is an apocalyptic number.

It is an amenable number.

31221225457 is a deficient number, since it is larger than the sum of its proper divisors (1).

31221225457 is an equidigital number, since it uses as much as digits as its factorization.

31221225457 is an evil number, because the sum of its binary digits is even.

The product of its digits is 33600, while the sum is 34.

The spelling of 31221225457 in words is "thirty-one billion, two hundred twenty-one million, two hundred twenty-five thousand, four hundred fifty-seven".