31331428 has 12 divisors (see below), whose sum is σ = 57214080. Its totient is φ = 14984552.

The previous prime is 31331407. The next prime is 31331429. The reversal of 31331428 is 82413313.

It is not an unprimeable number, because it can be changed into a prime (31331429) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 170188 + ... + 170371.

It is an arithmetic number, because the mean of its divisors is an integer number (4767840).

Almost surely, 2^31331428 is an apocalyptic number.

It is an amenable number.

31331428 is a deficient number, since it is larger than the sum of its proper divisors (25882652).

31331428 is a wasteful number, since it uses less digits than its factorization.

31331428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340586 (or 340584 counting only the distinct ones).

The product of its digits is 1728, while the sum is 25.

The square root of 31331428 is about 5597.4483472382. The cubic root of 31331428 is about 315.2536061309.

The spelling of 31331428 in words is "thirty-one million, three hundred thirty-one thousand, four hundred twenty-eight".