31561228 has 6 divisors (see below), whose sum is σ = 55232156. Its totient is φ = 15780612.

The previous prime is 31561199. The next prime is 31561237. The reversal of 31561228 is 82216513.

It is a super-2 number, since 2×31561228² = 1992222225735968, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31561196 and 31561205.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3945150 + ... + 3945157.

Almost surely, 2^31561228 is an apocalyptic number.

It is an amenable number.

31561228 is a deficient number, since it is larger than the sum of its proper divisors (23670928).

31561228 is a wasteful number, since it uses less digits than its factorization.

31561228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7890311 (or 7890309 counting only the distinct ones).

The product of its digits is 2880, while the sum is 28.

The square root of 31561228 is about 5617.9380559063. The cubic root of 31561228 is about 316.0224707623.

The spelling of 31561228 in words is "thirty-one million, five hundred sixty-one thousand, two hundred twenty-eight".