31222157 has 2 divisors, whose sum is σ = 31222158. Its totient is φ = 31222156.

The previous prime is 31222133. The next prime is 31222211. The reversal of 31222157 is 75122213.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 29278921 + 1943236 = 5411^2 + 1394^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31222157 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31222127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15611078 + 15611079.

It is an arithmetic number, because the mean of its divisors is an integer number (15611079).

Almost surely, 2^31222157 is an apocalyptic number.

It is an amenable number.

31222157 is a deficient number, since it is larger than the sum of its proper divisors (1).

31222157 is an equidigital number, since it uses as much as digits as its factorization.

31222157 is an evil number, because the sum of its binary digits is even.

The product of its digits is 840, while the sum is 23.

The square root of 31222157 is about 5587.6790351630. The cubic root of 31222157 is about 314.8866880592.

The spelling of 31222157 in words is "thirty-one million, two hundred twenty-two thousand, one hundred fifty-seven".