31643994 has 32 divisors (see below), whose sum is σ = 66424320. Its totient is φ = 10036800.

The previous prime is 31643993. The next prime is 31644029. The reversal of 31643994 is 49934613.

It is not an unprimeable number, because it can be changed into a prime (31643993) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9952 + ... + 12740.

It is an arithmetic number, because the mean of its divisors is an integer number (2075760).

Almost surely, 2^31643994 is an apocalyptic number.

31643994 is an abundant number, since it is smaller than the sum of its proper divisors (34780326).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31643994 is a wasteful number, since it uses less digits than its factorization.

31643994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2886.

The product of its digits is 69984, while the sum is 39.

The square root of 31643994 is about 5625.2994586955. The cubic root of 31643994 is about 316.2984748661.

The spelling of 31643994 in words is "thirty-one million, six hundred forty-three thousand, nine hundred ninety-four".