31392909 has 12 divisors (see below), whose sum is σ = 46571356. Its totient is φ = 20362752.

The previous prime is 31392871. The next prime is 31392929. The reversal of 31392909 is 90929313.

It can be written as a sum of positive squares in 2 ways, for example, as 16990884 + 14402025 = 4122^2 + 3795^2 .

It is not a de Polignac number, because 31392909 - 2⁹ = 31392397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31392929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 46804 + ... + 47469.

Almost surely, 2^31392909 is an apocalyptic number.

It is an amenable number.

31392909 is a deficient number, since it is larger than the sum of its proper divisors (15178447).

31392909 is a wasteful number, since it uses less digits than its factorization.

31392909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94316 (or 94313 counting only the distinct ones).

The product of its (nonzero) digits is 13122, while the sum is 36.

The square root of 31392909 is about 5602.9375331160. The cubic root of 31392909 is about 315.4596765666.

The spelling of 31392909 in words is "thirty-one million, three hundred ninety-two thousand, nine hundred nine".