31139806 has 4 divisors (see below), whose sum is σ = 46709712. Its totient is φ = 15569902.

The previous prime is 31139789. The next prime is 31139807. The reversal of 31139806 is 60893113.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31139807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7784950 + ... + 7784953.

It is an arithmetic number, because the mean of its divisors is an integer number (11677428).

Almost surely, 2^31139806 is an apocalyptic number.

31139806 is a deficient number, since it is larger than the sum of its proper divisors (15569906).

31139806 is a wasteful number, since it uses less digits than its factorization.

31139806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15569905.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 31139806 is about 5580.3051887867. The cubic root of 31139806 is about 314.6095978110.

The spelling of 31139806 in words is "thirty-one million, one hundred thirty-nine thousand, eight hundred six".