20664089 has 4 divisors (see below), whose sum is σ = 20706000. Its totient is φ = 20622180.

The previous prime is 20664031. The next prime is 20664113. The reversal of 20664089 is 98046602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20664089 - 2⁸ = 20663833 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20664289) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20207 + ... + 21204.

It is an arithmetic number, because the mean of its divisors is an integer number (5176500).

Almost surely, 2^20664089 is an apocalyptic number.

It is an amenable number.

20664089 is a deficient number, since it is larger than the sum of its proper divisors (41911).

20664089 is an equidigital number, since it uses as much as digits as its factorization.

20664089 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41910.

The product of its (nonzero) digits is 20736, while the sum is 35.

The square root of 20664089 is about 4545.7770512862. Note that the first 3 decimals coincide. The cubic root of 20664089 is about 274.4134672606.

The spelling of 20664089 in words is "twenty million, six hundred sixty-four thousand, eighty-nine".