31900039 has 4 divisors (see below), whose sum is σ = 32133024. Its totient is φ = 31667056.

The previous prime is 31900019. The next prime is 31900067. The reversal of 31900039 is 93000913.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93000913 = 653 ⋅142421.

It is a cyclic number.

It is not a de Polignac number, because 31900039 - 2⁷ = 31899911 is a prime.

It is a super-2 number, since 2×31900039² = 2035224976403042, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31899986 and 31900022.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31900019) 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 3 ways as a sum of consecutive naturals, for example, 116287 + ... + 116560.

It is an arithmetic number, because the mean of its divisors is an integer number (8033256).

Almost surely, 2^31900039 is an apocalyptic number.

31900039 is a deficient number, since it is larger than the sum of its proper divisors (232985).

31900039 is a wasteful number, since it uses less digits than its factorization.

31900039 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 232984.

The product of its (nonzero) digits is 729, while the sum is 25.

The square root of 31900039 is about 5648.0119511205. The cubic root of 31900039 is about 317.1492859994.

The spelling of 31900039 in words is "thirty-one million, nine hundred thousand, thirty-nine".