31309228 has 6 divisors (see below), whose sum is σ = 54791156. Its totient is φ = 15654612.

The previous prime is 31309217. The next prime is 31309231. The reversal of 31309228 is 82290313.

It is a junction number, because it is equal to n+sod(n) for n = 31309196 and 31309205.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3913650 + ... + 3913657.

Almost surely, 2^31309228 is an apocalyptic number.

It is an amenable number.

31309228 is a deficient number, since it is larger than the sum of its proper divisors (23481928).

31309228 is a wasteful number, since it uses less digits than its factorization.

31309228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7827311 (or 7827309 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 31309228 is about 5595.4649494032. The cubic root of 31309228 is about 315.1791304992.

The spelling of 31309228 in words is "thirty-one million, three hundred nine thousand, two hundred twenty-eight".