20666321 has 8 divisors (see below), whose sum is σ = 22538880. Its totient is φ = 18834192.

The previous prime is 20666311. The next prime is 20666333. The reversal of 20666321 is 12366602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20666321 - 2⁶ = 20666257 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20666311) 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, 9035 + ... + 11088.

It is an arithmetic number, because the mean of its divisors is an integer number (2817360).

Almost surely, 2^20666321 is an apocalyptic number.

It is an amenable number.

20666321 is a deficient number, since it is larger than the sum of its proper divisors (1872559).

20666321 is a wasteful number, since it uses less digits than its factorization.

20666321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20215.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 20666321 is about 4546.0225472384. The cubic root of 20666321 is about 274.4233470220.

The spelling of 20666321 in words is "twenty million, six hundred sixty-six thousand, three hundred twenty-one".