31128330 has 16 divisors (see below), whose sum is σ = 74708064. Its totient is φ = 8300880.

The previous prime is 31128323. The next prime is 31128379. The reversal of 31128330 is 3382113.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 31128297 and 31128306.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 518776 + ... + 518835.

It is an arithmetic number, because the mean of its divisors is an integer number (4669254).

Almost surely, 2^31128330 is an apocalyptic number.

31128330 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

31128330 is an abundant number, since it is smaller than the sum of its proper divisors (43579734).

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

31128330 is a wasteful number, since it uses less digits than its factorization.

31128330 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1037621.

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 31128330 is about 5579.2768348595. The cubic root of 31128330 is about 314.5709452114.

The spelling of 31128330 in words is "thirty-one million, one hundred twenty-eight thousand, three hundred thirty".