31394387 has 2 divisors, whose sum is σ = 31394388. Its totient is φ = 31394386.

The previous prime is 31394369. The next prime is 31394399. The reversal of 31394387 is 78349313.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31394387 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31394387.

It is not a weakly prime, because it can be changed into another prime (31394887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15697193 + 15697194.

It is an arithmetic number, because the mean of its divisors is an integer number (15697194).

Almost surely, 2^31394387 is an apocalyptic number.

31394387 is a deficient number, since it is larger than the sum of its proper divisors (1).

31394387 is an equidigital number, since it uses as much as digits as its factorization.

31394387 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 38.

The square root of 31394387 is about 5603.0694266625. The cubic root of 31394387 is about 315.4646271759.

The spelling of 31394387 in words is "thirty-one million, three hundred ninety-four thousand, three hundred eighty-seven".