631399 has 2 divisors, whose sum is σ = 631400. Its totient is φ = 631398.

The previous prime is 631391. The next prime is 631409. The reversal of 631399 is 993136.

631399 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 631399 - 2³ = 631391 is a prime.

It is a Chen prime.

It is an Ulam number.

631399 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 631399.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (631391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315699 + 315700.

It is an arithmetic number, because the mean of its divisors is an integer number (315700).

2⁶³¹³⁹⁹ is an apocalyptic number.

631399 is a deficient number, since it is larger than the sum of its proper divisors (1).

631399 is an equidigital number, since it uses as much as digits as its factorization.

631399 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4374, while the sum is 31.

The square root of 631399 is about 794.6061917705. The cubic root of 631399 is about 85.7895974333.

The spelling of 631399 in words is "six hundred thirty-one thousand, three hundred ninety-nine".