20668769 has 4 divisors (see below), whose sum is σ = 22547760. Its totient is φ = 18789780.

The previous prime is 20668759. The next prime is 20668771. The reversal of 20668769 is 96786602.

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 a de Polignac number, because none of the positive numbers 2^k-20668769 is a prime.

It is a super-3 number, since 3×20668769³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20668759) 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, 939479 + ... + 939500.

It is an arithmetic number, because the mean of its divisors is an integer number (5636940).

Almost surely, 2^20668769 is an apocalyptic number.

It is an amenable number.

20668769 is a deficient number, since it is larger than the sum of its proper divisors (1878991).

20668769 is a wasteful number, since it uses less digits than its factorization.

20668769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1878990.

The product of its (nonzero) digits is 217728, while the sum is 44.

The square root of 20668769 is about 4546.2917856205. The cubic root of 20668769 is about 274.4341820714.

The spelling of 20668769 in words is "twenty million, six hundred sixty-eight thousand, seven hundred sixty-nine".