31400399 has 2 divisors, whose sum is σ = 31400400. Its totient is φ = 31400398.

The previous prime is 31400323. The next prime is 31400401. The reversal of 31400399 is 99300413.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31400399 - 2⁸ = 31400143 is a prime.

Together with 31400401, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31400099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15700199 + 15700200.

It is an arithmetic number, because the mean of its divisors is an integer number (15700200).

Almost surely, 2^31400399 is an apocalyptic number.

31400399 is a deficient number, since it is larger than the sum of its proper divisors (1).

31400399 is an equidigital number, since it uses as much as digits as its factorization.

31400399 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2916, while the sum is 29.

The square root of 31400399 is about 5603.6058926373. The cubic root of 31400399 is about 315.4847629653.

The spelling of 31400399 in words is "thirty-one million, four hundred thousand, three hundred ninety-nine".