631030391 has 2 divisors, whose sum is σ = 631030392. Its totient is φ = 631030390.

The previous prime is 631030373. The next prime is 631030399. The reversal of 631030391 is 193030136.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-631030391 is a prime.

It is a super-2 number, since 2×631030391² = 796398708731225762, which contains 22 as substring.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 631030391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (631030399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315515195 + 315515196.

It is an arithmetic number, because the mean of its divisors is an integer number (315515196).

Almost surely, 2^631030391 is an apocalyptic number.

631030391 is a deficient number, since it is larger than the sum of its proper divisors (1).

631030391 is an equidigital number, since it uses as much as digits as its factorization.

631030391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1458, while the sum is 26.

The square root of 631030391 is about 25120.3182901810. The cubic root of 631030391 is about 857.7289960649.

The spelling of 631030391 in words is "six hundred thirty-one million, thirty thousand, three hundred ninety-one".