31664671 has 4 divisors (see below), whose sum is σ = 32686144. Its totient is φ = 30643200.

The previous prime is 31664663. The next prime is 31664729. The reversal of 31664671 is 17646613.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 31664671 - 2³ = 31664663 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 (31664071) 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, 510690 + ... + 510751.

It is an arithmetic number, because the mean of its divisors is an integer number (8171536).

Almost surely, 2^31664671 is an apocalyptic number.

31664671 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

31664671 is a deficient number, since it is larger than the sum of its proper divisors (1021473).

31664671 is a wasteful number, since it uses less digits than its factorization.

31664671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1021472.

The product of its digits is 18144, while the sum is 34.

The square root of 31664671 is about 5627.1370162810. The cubic root of 31664671 is about 316.3673523872.

The spelling of 31664671 in words is "thirty-one million, six hundred sixty-four thousand, six hundred seventy-one".