20665707 has 16 divisors (see below), whose sum is σ = 29299968. Its totient is φ = 12927200.

The previous prime is 20665669. The next prime is 20665739. The reversal of 20665707 is 70756602.

It is a cyclic number.

It is not a de Polignac number, because 20665707 - 2⁸ = 20665451 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (20665207) 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, 832 + ... + 6482.

It is an arithmetic number, because the mean of its divisors is an integer number (1831248).

Almost surely, 2^20665707 is an apocalyptic number.

20665707 is a deficient number, since it is larger than the sum of its proper divisors (8634261).

20665707 is a wasteful number, since it uses less digits than its factorization.

20665707 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5730.

The product of its (nonzero) digits is 17640, while the sum is 33.

The square root of 20665707 is about 4545.9550151756. The cubic root of 20665707 is about 274.4206292732.

The spelling of 20665707 in words is "twenty million, six hundred sixty-five thousand, seven hundred seven".