31139047 has 2 divisors, whose sum is σ = 31139048. Its totient is φ = 31139046.

The previous prime is 31139041. The next prime is 31139057. The reversal of 31139047 is 74093113.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31139047 - 2³ = 31139039 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31139041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15569523 + 15569524.

It is an arithmetic number, because the mean of its divisors is an integer number (15569524).

Almost surely, 2^31139047 is an apocalyptic number.

31139047 is a deficient number, since it is larger than the sum of its proper divisors (1).

31139047 is an equidigital number, since it uses as much as digits as its factorization.

31139047 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2268, while the sum is 28.

The square root of 31139047 is about 5580.2371813392. The cubic root of 31139047 is about 314.6070416976.

The spelling of 31139047 in words is "thirty-one million, one hundred thirty-nine thousand, forty-seven".