31030128 has 120 divisors (see below), whose sum is σ = 94243968. Its totient is φ = 9865152.

The previous prime is 31030127. The next prime is 31030157. The reversal of 31030128 is 82103013.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a self number, because there is not a number n which added to its sum of digits gives 31030128.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31030123) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 89251 + ... + 89597.

Almost surely, 2^31030128 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31030128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47121984).

31030128 is an abundant number, since it is smaller than the sum of its proper divisors (63213840).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31030128 is a wasteful number, since it uses less digits than its factorization.

31030128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 393 (or 375 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 31030128 is about 5570.4692800517. The cubic root of 31030128 is about 314.2397995105.

The spelling of 31030128 in words is "thirty-one million, thirty thousand, one hundred twenty-eight".