31890128 has 40 divisors (see below), whose sum is σ = 63886536. Its totient is φ = 15411200.

The previous prime is 31890127. The next prime is 31890137. The reversal of 31890128 is 82109813.

It can be written as a sum of positive squares in 4 ways, for example, as 5798464 + 26091664 = 2408^2 + 5108^2 .

It is a junction number, because it is equal to n+sod(n) for n = 31890094 and 31890103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31890127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 113348 + ... + 113628.

Almost surely, 2^31890128 is an apocalyptic number.

It is an amenable number.

31890128 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

31890128 is a wasteful number, since it uses less digits than its factorization.

31890128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 503 (or 497 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 31890128 is about 5647.1344945910. The cubic root of 31890128 is about 317.1164376367.

The spelling of 31890128 in words is "thirty-one million, eight hundred ninety thousand, one hundred twenty-eight".