201720671 has 4 divisors (see below), whose sum is σ = 202625472. Its totient is φ = 200815872.

The previous prime is 201720667. The next prime is 201720677. The reversal of 201720671 is 176027102.

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

It is a cyclic number.

It is not a de Polignac number, because 201720671 - 2² = 201720667 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 201720671.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201720677) 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, 452066 + ... + 452511.

It is an arithmetic number, because the mean of its divisors is an integer number (50656368).

Almost surely, 2^201720671 is an apocalyptic number.

201720671 is a deficient number, since it is larger than the sum of its proper divisors (904801).

201720671 is an equidigital number, since it uses as much as digits as its factorization.

201720671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 904800.

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

The square root of 201720671 is about 14202.8402441202. The cubic root of 201720671 is about 586.4758518053.

Adding to 201720671 its reverse (176027102), we get a palindrome (377747773).

The spelling of 201720671 in words is "two hundred one million, seven hundred twenty thousand, six hundred seventy-one".