20664091 has 8 divisors (see below), whose sum is σ = 23657984. Its totient is φ = 17680680.

The previous prime is 20664031. The next prime is 20664113. The reversal of 20664091 is 19046602.

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-20664091 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20664031) 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, 2206 + ... + 6796.

It is an arithmetic number, because the mean of its divisors is an integer number (2957248).

Almost surely, 2^20664091 is an apocalyptic number.

20664091 is a deficient number, since it is larger than the sum of its proper divisors (2993893).

20664091 is an equidigital number, since it uses as much as digits as its factorization.

20664091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5241.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 20664091 is about 4545.7772712706. Note that the first 3 decimals coincide. The cubic root of 20664091 is about 274.4134761137.

The spelling of 20664091 in words is "twenty million, six hundred sixty-four thousand, ninety-one".