31999090 has 16 divisors (see below), whose sum is σ = 58021272. Its totient is φ = 12705664.

The previous prime is 31999087. The next prime is 31999103. The reversal of 31999090 is 9099913.

It can be written as a sum of positive squares in 4 ways, for example, as 30019441 + 1979649 = 5479^2 + 1407^2 .

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 in 7 ways as a sum of consecutive naturals, for example, 10309 + ... + 13048.

Almost surely, 2^31999090 is an apocalyptic number.

31999090 is a deficient number, since it is larger than the sum of its proper divisors (26022182).

31999090 is a wasteful number, since it uses less digits than its factorization.

31999090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23501.

The product of its (nonzero) digits is 19683, while the sum is 40.

The square root of 31999090 is about 5656.7738155242. The cubic root of 31999090 is about 317.4772009173.

The spelling of 31999090 in words is "thirty-one million, nine hundred ninety-nine thousand, ninety".