31225861 has 2 divisors, whose sum is σ = 31225862. Its totient is φ = 31225860.

The previous prime is 31225853. The next prime is 31225903. The reversal of 31225861 is 16852213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16248961 + 14976900 = 4031^2 + 3870^2 .

It is a cyclic number.

It is not a de Polignac number, because 31225861 - 2³ = 31225853 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31225801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15612930 + 15612931.

It is an arithmetic number, because the mean of its divisors is an integer number (15612931).

Almost surely, 2^31225861 is an apocalyptic number.

It is an amenable number.

31225861 is a deficient number, since it is larger than the sum of its proper divisors (1).

31225861 is an equidigital number, since it uses as much as digits as its factorization.

31225861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2880, while the sum is 28.

The square root of 31225861 is about 5588.0104688520. The cubic root of 31225861 is about 314.8991396245.

The spelling of 31225861 in words is "thirty-one million, two hundred twenty-five thousand, eight hundred sixty-one".