39666665 has 8 divisors (see below), whose sum is σ = 47786760. Its totient is φ = 31608832.

The previous prime is 39666629. The next prime is 39666691. The reversal of 39666665 is 56666693.

It can be written as a sum of positive squares in 4 ways, for example, as 5139289 + 34527376 = 2267^2 + 5876^2 .

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 39666665 - 2¹² = 39662569 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14150 + ... + 16719.

It is an arithmetic number, because the mean of its divisors is an integer number (5973345).

Almost surely, 2^39666665 is an apocalyptic number.

It is an amenable number.

39666665 is a deficient number, since it is larger than the sum of its proper divisors (8120095).

39666665 is a wasteful number, since it uses less digits than its factorization.

39666665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31131.

The product of its digits is 1049760, while the sum is 47.

The square root of 39666665 is about 6298.1477435830. The cubic root of 39666665 is about 341.0425467848.

The spelling of 39666665 in words is "thirty-nine million, six hundred sixty-six thousand, six hundred sixty-five".