31663689 has 4 divisors (see below), whose sum is σ = 42218256. Its totient is φ = 21109124.

The previous prime is 31663669. The next prime is 31663691. The reversal of 31663689 is 98636613.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 31663689 - 2⁷ = 31663561 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 31663689.

It is not an unprimeable number, because it can be changed into a prime (31663649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5277279 + ... + 5277284.

It is an arithmetic number, because the mean of its divisors is an integer number (10554564).

Almost surely, 2^31663689 is an apocalyptic number.

It is an amenable number.

31663689 is a deficient number, since it is larger than the sum of its proper divisors (10554567).

31663689 is a wasteful number, since it uses less digits than its factorization.

31663689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10554566.

The product of its digits is 139968, while the sum is 42.

The square root of 31663689 is about 5627.0497598653. The cubic root of 31663689 is about 316.3640819079.

The spelling of 31663689 in words is "thirty-one million, six hundred sixty-three thousand, six hundred eighty-nine".