631981994 has 32 divisors (see below), whose sum is σ = 1132690176. Its totient is φ = 258572160.

The previous prime is 631981979. The next prime is 631982023. The reversal of 631981994 is 499189136.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 197084 + ... + 200264.

It is an arithmetic number, because the mean of its divisors is an integer number (35396568).

Almost surely, 2^631981994 is an apocalyptic number.

631981994 is a deficient number, since it is larger than the sum of its proper divisors (500708182).

631981994 is a wasteful number, since it uses less digits than its factorization.

631981994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3830.

The product of its digits is 419904, while the sum is 50.

The square root of 631981994 is about 25139.2520572908. The cubic root of 631981994 is about 858.1599354468.

The spelling of 631981994 in words is "six hundred thirty-one million, nine hundred eighty-one thousand, nine hundred ninety-four".