31961257 has 4 divisors (see below), whose sum is σ = 31982596. Its totient is φ = 31939920.

The previous prime is 31961233. The next prime is 31961261. The reversal of 31961257 is 75216913.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12033961 + 19927296 = 3469^2 + 4464^2 .

It is a cyclic number.

It is not a de Polignac number, because 31961257 - 2¹¹ = 31959209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31961227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8238 + ... + 11479.

It is an arithmetic number, because the mean of its divisors is an integer number (7995649).

Almost surely, 2^31961257 is an apocalyptic number.

It is an amenable number.

31961257 is a deficient number, since it is larger than the sum of its proper divisors (21339).

31961257 is a wasteful number, since it uses less digits than its factorization.

31961257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21338.

The product of its digits is 11340, while the sum is 34.

The square root of 31961257 is about 5653.4287826062. The cubic root of 31961257 is about 317.3520322360.

The spelling of 31961257 in words is "thirty-one million, nine hundred sixty-one thousand, two hundred fifty-seven".