20664097 has 4 divisors (see below), whose sum is σ = 21562560. Its totient is φ = 19765636.

The previous prime is 20664031. The next prime is 20664113. The reversal of 20664097 is 79046602.

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, and also an emirpimes, since its reverse is a distinct semiprime: 79046602 = 2 ⋅39523301.

It is a cyclic number.

It is not a de Polignac number, because 20664097 - 2⁷ = 20663969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20764097) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 449197 + ... + 449242.

It is an arithmetic number, because the mean of its divisors is an integer number (5390640).

Almost surely, 2^20664097 is an apocalyptic number.

It is an amenable number.

20664097 is a deficient number, since it is larger than the sum of its proper divisors (898463).

20664097 is an equidigital number, since it uses as much as digits as its factorization.

20664097 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 898462.

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 20664097 is about 4545.7779312237. Note that the first 3 decimals coincide. The cubic root of 20664097 is about 274.4135026732.

The spelling of 20664097 in words is "twenty million, six hundred sixty-four thousand, ninety-seven".