31423257 has 6 divisors (see below), whose sum is σ = 45389162. Its totient is φ = 20948832.

The previous prime is 31423253. The next prime is 31423291. The reversal of 31423257 is 75232413.

It can be written as a sum of positive squares in only one way, i.e., 24890121 + 6533136 = 4989^2 + 2556^2 .

It is not a de Polignac number, because 31423257 - 2² = 31423253 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31423257.

It is not an unprimeable number, because it can be changed into a prime (31423253) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1745728 + ... + 1745745.

Almost surely, 2^31423257 is an apocalyptic number.

It is an amenable number.

31423257 is a deficient number, since it is larger than the sum of its proper divisors (13965905).

31423257 is a wasteful number, since it uses less digits than its factorization.

31423257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3491479 (or 3491476 counting only the distinct ones).

The product of its digits is 5040, while the sum is 27.

The square root of 31423257 is about 5605.6451011458. The cubic root of 31423257 is about 315.5612970413.

The spelling of 31423257 in words is "thirty-one million, four hundred twenty-three thousand, two hundred fifty-seven".