31890725 has 12 divisors (see below), whose sum is σ = 41871204. Its totient is φ = 24011520.

The previous prime is 31890709. The next prime is 31890731. The reversal of 31890725 is 52709813.

It can be written as a sum of positive squares in 6 ways, for example, as 2362369 + 29528356 = 1537^2 + 5434^2 .

It is not a de Polignac number, because 31890725 - 2⁴ = 31890709 is a prime.

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 37094 + ... + 37943.

It is an arithmetic number, because the mean of its divisors is an integer number (3489267).

Almost surely, 2^31890725 is an apocalyptic number.

It is an amenable number.

31890725 is a deficient number, since it is larger than the sum of its proper divisors (9980479).

31890725 is a wasteful number, since it uses less digits than its factorization.

31890725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75064 (or 75059 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 31890725 is about 5647.1873530103. The cubic root of 31890725 is about 317.1184164866.

The spelling of 31890725 in words is "thirty-one million, eight hundred ninety thousand, seven hundred twenty-five".