20665091 has 8 divisors (see below), whose sum is σ = 21008064. Its totient is φ = 20324520.

The previous prime is 20665067. The next prime is 20665093. The reversal of 20665091 is 19056602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20665091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20665093) 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, 25076 + ... + 25886.

It is an arithmetic number, because the mean of its divisors is an integer number (2626008).

Almost surely, 2^20665091 is an apocalyptic number.

20665091 is a deficient number, since it is larger than the sum of its proper divisors (342973).

20665091 is an equidigital number, since it uses as much as digits as its factorization.

20665091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1201.

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 20665091 is about 4545.8872621305. The cubic root of 20665091 is about 274.4179026178.

The spelling of 20665091 in words is "twenty million, six hundred sixty-five thousand, ninety-one".