31665945 has 16 divisors (see below), whose sum is σ = 50749632. Its totient is φ = 16860480.

The previous prime is 31665943. The next prime is 31665961. The reversal of 31665945 is 54956613.

It is not a de Polignac number, because 31665945 - 2¹ = 31665943 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31665943) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10230 + ... + 12960.

It is an arithmetic number, because the mean of its divisors is an integer number (3171852).

Almost surely, 2^31665945 is an apocalyptic number.

It is an amenable number.

31665945 is a deficient number, since it is larger than the sum of its proper divisors (19083687).

31665945 is a wasteful number, since it uses less digits than its factorization.

31665945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3512.

The product of its digits is 97200, while the sum is 39.

The square root of 31665945 is about 5627.2502165800. The cubic root of 31665945 is about 316.3715952504.

The spelling of 31665945 in words is "thirty-one million, six hundred sixty-five thousand, nine hundred forty-five".