31664399 has 16 divisors (see below), whose sum is σ = 35888832. Its totient is φ = 27717888.

The previous prime is 31664377. The next prime is 31664419. The reversal of 31664399 is 99346613.

It is a cyclic number.

It is not a de Polignac number, because 31664399 - 2¹⁶ = 31598863 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31664309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40577 + ... + 41349.

It is an arithmetic number, because the mean of its divisors is an integer number (2243052).

Almost surely, 2^31664399 is an apocalyptic number.

31664399 is a deficient number, since it is larger than the sum of its proper divisors (4224433).

31664399 is a wasteful number, since it uses less digits than its factorization.

31664399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 946.

The product of its digits is 104976, while the sum is 41.

The square root of 31664399 is about 5627.1128476333. The cubic root of 31664399 is about 316.3664465179.

The spelling of 31664399 in words is "thirty-one million, six hundred sixty-four thousand, three hundred ninety-nine".