631900391 has 2 divisors, whose sum is σ = 631900392. Its totient is φ = 631900390.

The previous prime is 631900361. The next prime is 631900429. The reversal of 631900391 is 193009136.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-631900391 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (631900301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315950195 + 315950196.

It is an arithmetic number, because the mean of its divisors is an integer number (315950196).

Almost surely, 2^631900391 is an apocalyptic number.

631900391 is a deficient number, since it is larger than the sum of its proper divisors (1).

631900391 is an equidigital number, since it uses as much as digits as its factorization.

631900391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4374, while the sum is 32.

The square root of 631900391 is about 25137.6289852484. The cubic root of 631900391 is about 858.1229979811.

The spelling of 631900391 in words is "six hundred thirty-one million, nine hundred thousand, three hundred ninety-one".