20672171 has 16 divisors (see below), whose sum is σ = 23654400. Its totient is φ = 17908128.

The previous prime is 20672131. The next prime is 20672227. The reversal of 20672171 is 17127602.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20672171 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20672171.

It is not an unprimeable number, because it can be changed into a prime (20672131) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31040 + ... + 31698.

It is an arithmetic number, because the mean of its divisors is an integer number (1478400).

Almost surely, 2^20672171 is an apocalyptic number.

20672171 is a deficient number, since it is larger than the sum of its proper divisors (2982229).

20672171 is a wasteful number, since it uses less digits than its factorization.

20672171 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 818.

The product of its (nonzero) digits is 1176, while the sum is 26.

The square root of 20672171 is about 4546.6659213098. The cubic root of 20672171 is about 274.4492381829.

Adding to 20672171 its reverse (17127602), we get a palindrome (37799773).

The spelling of 20672171 in words is "twenty million, six hundred seventy-two thousand, one hundred seventy-one".