20668171 has 4 divisors (see below), whose sum is σ = 20959344. Its totient is φ = 20377000.

The previous prime is 20668169. The next prime is 20668183. The reversal of 20668171 is 17186602.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20668171 - 2¹ = 20668169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20668111) 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, 145480 + ... + 145621.

It is an arithmetic number, because the mean of its divisors is an integer number (5239836).

Almost surely, 2^20668171 is an apocalyptic number.

20668171 is a deficient number, since it is larger than the sum of its proper divisors (291173).

20668171 is an equidigital number, since it uses as much as digits as its factorization.

20668171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 291172.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 20668171 is about 4546.2260172587. The cubic root of 20668171 is about 274.4315353532.

The spelling of 20668171 in words is "twenty million, six hundred sixty-eight thousand, one hundred seventy-one".