20668969 has 4 divisors (see below), whose sum is σ = 20684160. Its totient is φ = 20653780.

The previous prime is 20668931. The next prime is 20668997. The reversal of 20668969 is 96986602.

It is a happy number.

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 20668969 - 2⁷ = 20668841 is a prime.

It is a super-2 number, since 2×20668969² = 854412559045922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20668919) 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, 5329 + ... + 8350.

It is an arithmetic number, because the mean of its divisors is an integer number (5171040).

Almost surely, 2^20668969 is an apocalyptic number.

It is an amenable number.

20668969 is a deficient number, since it is larger than the sum of its proper divisors (15191).

20668969 is a wasteful number, since it uses less digits than its factorization.

20668969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15190.

The product of its (nonzero) digits is 279936, while the sum is 46.

The square root of 20668969 is about 4546.3137815157. The cubic root of 20668969 is about 274.4350672501.

The spelling of 20668969 in words is "twenty million, six hundred sixty-eight thousand, nine hundred sixty-nine".