20668161 has 8 divisors (see below), whose sum is σ = 27648544. Its totient is φ = 13733280.

The previous prime is 20668157. The next prime is 20668169. The reversal of 20668161 is 16186602.

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

It is not a de Polignac number, because 20668161 - 2² = 20668157 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20668169) 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 7 ways as a sum of consecutive naturals, for example, 10300 + ... + 12141.

It is an arithmetic number, because the mean of its divisors is an integer number (3456068).

Almost surely, 2^20668161 is an apocalyptic number.

It is an amenable number.

20668161 is a deficient number, since it is larger than the sum of its proper divisors (6980383).

20668161 is a wasteful number, since it uses less digits than its factorization.

20668161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22751.

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 20668161 is about 4546.2249174452. The cubic root of 20668161 is about 274.4314910933.

The spelling of 20668161 in words is "twenty million, six hundred sixty-eight thousand, one hundred sixty-one".