31638661 has 8 divisors (see below), whose sum is σ = 32394240. Its totient is φ = 30886608.

The previous prime is 31638653. The next prime is 31638697. The reversal of 31638661 is 16683613.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31638661 - 2³ = 31638653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31638601) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 27975 + ... + 29083.

It is an arithmetic number, because the mean of its divisors is an integer number (4049280).

Almost surely, 2^31638661 is an apocalyptic number.

It is an amenable number.

31638661 is a deficient number, since it is larger than the sum of its proper divisors (755579).

31638661 is a wasteful number, since it uses less digits than its factorization.

31638661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1763.

The product of its digits is 15552, while the sum is 34.

The square root of 31638661 is about 5624.8254195130. The cubic root of 31638661 is about 316.2807051483.

The spelling of 31638661 in words is "thirty-one million, six hundred thirty-eight thousand, six hundred sixty-one".