631893891 has 4 divisors (see below), whose sum is σ = 842525192. Its totient is φ = 421262592.

The previous prime is 631893883. The next prime is 631893907. The reversal of 631893891 is 198398136.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 631893891 - 2³ = 631893883 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 631893891.

It is not an unprimeable number, because it can be changed into a prime (631893391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 105315646 + ... + 105315651.

It is an arithmetic number, because the mean of its divisors is an integer number (210631298).

Almost surely, 2^631893891 is an apocalyptic number.

631893891 is a deficient number, since it is larger than the sum of its proper divisors (210631301).

631893891 is a wasteful number, since it uses less digits than its factorization.

631893891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210631300.

The product of its digits is 279936, while the sum is 48.

The square root of 631893891 is about 25137.4996966683. The cubic root of 631893891 is about 858.1200556299.

The spelling of 631893891 in words is "six hundred thirty-one million, eight hundred ninety-three thousand, eight hundred ninety-one".