31139855 has 4 divisors (see below), whose sum is σ = 37367832. Its totient is φ = 24911880.

The previous prime is 31139821. The next prime is 31139863. The reversal of 31139855 is 55893113.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 55893113 = 83 ⋅673411.

It is not a de Polignac number, because 31139855 - 2¹⁶ = 31074319 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 3113981 + ... + 3113990.

It is an arithmetic number, because the mean of its divisors is an integer number (9341958).

Almost surely, 2^31139855 is an apocalyptic number.

31139855 is a deficient number, since it is larger than the sum of its proper divisors (6227977).

31139855 is an equidigital number, since it uses as much as digits as its factorization.

31139855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6227976.

The product of its digits is 16200, while the sum is 35.

The square root of 31139855 is about 5580.3095792259. The cubic root of 31139855 is about 314.6097628288.

The spelling of 31139855 in words is "thirty-one million, one hundred thirty-nine thousand, eight hundred fifty-five".