31223105857 has 2 divisors, whose sum is σ = 31223105858. Its totient is φ = 31223105856.

The previous prime is 31223105741. The next prime is 31223105873. The reversal of 31223105857 is 75850132213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16219550736 + 15003555121 = 127356^2 + 122489^2 .

It is an emirp because it is prime and its reverse (75850132213) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31223105857 is a prime.

It is not a weakly prime, because it can be changed into another prime (31223105257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15611552928 + 15611552929.

It is an arithmetic number, because the mean of its divisors is an integer number (15611552929).

Almost surely, 2^31223105857 is an apocalyptic number.

It is an amenable number.

31223105857 is a deficient number, since it is larger than the sum of its proper divisors (1).

31223105857 is an equidigital number, since it uses as much as digits as its factorization.

31223105857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 50400, while the sum is 37.

The spelling of 31223105857 in words is "thirty-one billion, two hundred twenty-three million, one hundred five thousand, eight hundred fifty-seven".