20665307 has 8 divisors (see below), whose sum is σ = 22476720. Its totient is φ = 18885600.

The previous prime is 20665297. The next prime is 20665357. The reversal of 20665307 is 70356602.

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 20665307 - 2⁴ = 20665291 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20665307.

It is not an unprimeable number, because it can be changed into a prime (20665357) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6557 + ... + 9182.

It is an arithmetic number, because the mean of its divisors is an integer number (2809590).

Almost surely, 2^20665307 is an apocalyptic number.

20665307 is a deficient number, since it is larger than the sum of its proper divisors (1811413).

20665307 is a wasteful number, since it uses less digits than its factorization.

20665307 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15853.

The product of its (nonzero) digits is 7560, while the sum is 29.

The square root of 20665307 is about 4545.9110198067. The cubic root of 20665307 is about 274.4188587239.

The spelling of 20665307 in words is "twenty million, six hundred sixty-five thousand, three hundred seven".