31664240 has 20 divisors (see below), whose sum is σ = 73619544. Its totient is φ = 12665664.

The previous prime is 31664239. The next prime is 31664309. The reversal of 31664240 is 4246613.

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 197822 + ... + 197981.

Almost surely, 2^31664240 is an apocalyptic number.

It is an amenable number.

31664240 is an abundant number, since it is smaller than the sum of its proper divisors (41955304).

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

31664240 is a wasteful number, since it uses less digits than its factorization.

31664240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 395816 (or 395810 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 31664240 is about 5627.0987195890. The cubic root of 31664240 is about 316.3659169815.

The spelling of 31664240 in words is "thirty-one million, six hundred sixty-four thousand, two hundred forty".