631273891 has 2 divisors, whose sum is σ = 631273892. Its totient is φ = 631273890.

The previous prime is 631273889. The next prime is 631273897. The reversal of 631273891 is 198372136.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 631273891 - 2¹ = 631273889 is a prime.

Together with 631273889, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (631273897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315636945 + 315636946.

It is an arithmetic number, because the mean of its divisors is an integer number (315636946).

Almost surely, 2^631273891 is an apocalyptic number.

631273891 is a deficient number, since it is larger than the sum of its proper divisors (1).

631273891 is an equidigital number, since it uses as much as digits as its factorization.

631273891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 40.

The square root of 631273891 is about 25125.1644969739. The cubic root of 631273891 is about 857.8393077894.

The spelling of 631273891 in words is "six hundred thirty-one million, two hundred seventy-three thousand, eight hundred ninety-one".