20001671 has 4 divisors (see below), whose sum is σ = 20085600. Its totient is φ = 19917744.

The previous prime is 20001659. The next prime is 20001679. The reversal of 20001671 is 17610002.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20001671 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20001679) 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, 41606 + ... + 42083.

It is an arithmetic number, because the mean of its divisors is an integer number (5021400).

Almost surely, 2^20001671 is an apocalyptic number.

20001671 is a deficient number, since it is larger than the sum of its proper divisors (83929).

20001671 is an equidigital number, since it uses as much as digits as its factorization.

20001671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83928.

The product of its (nonzero) digits is 84, while the sum is 17.

The square root of 20001671 is about 4472.3227745770. The cubic root of 20001671 is about 271.4493211020.

Adding to 20001671 its reverse (17610002), we get a palindrome (37611673).

The spelling of 20001671 in words is "twenty million, one thousand, six hundred seventy-one".