31143691 has 2 divisors, whose sum is σ = 31143692. Its totient is φ = 31143690.

The previous prime is 31143689. The next prime is 31143703. The reversal of 31143691 is 19634113.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31143691 - 2¹ = 31143689 is a prime.

Together with 31143689, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (31143601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15571845 + 15571846.

It is an arithmetic number, because the mean of its divisors is an integer number (15571846).

Almost surely, 2^31143691 is an apocalyptic number.

31143691 is a deficient number, since it is larger than the sum of its proper divisors (1).

31143691 is an equidigital number, since it uses as much as digits as its factorization.

31143691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1944, while the sum is 28.

The square root of 31143691 is about 5580.6532771711. The cubic root of 31143691 is about 314.6226808240.

The spelling of 31143691 in words is "thirty-one million, one hundred forty-three thousand, six hundred ninety-one".