201651 has 4 divisors (see below), whose sum is σ = 268872. Its totient is φ = 134432.

The previous prime is 201629. The next prime is 201653. The reversal of 201651 is 156102.

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 201651 - 2⁹ = 201139 is a prime.

It is a D-number.

It is a nialpdrome in base 12.

It is a self number, because there is not a number n which added to its sum of digits gives 201651.

It is not an unprimeable number, because it can be changed into a prime (201653) 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, 33606 + ... + 33611.

It is an arithmetic number, because the mean of its divisors is an integer number (67218).

2²⁰¹⁶⁵¹ is an apocalyptic number.

201651 is a deficient number, since it is larger than the sum of its proper divisors (67221).

201651 is an equidigital number, since it uses as much as digits as its factorization.

201651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67220.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 201651 is about 449.0556758354. The cubic root of 201651 is about 58.6408324328.

Adding to 201651 its reverse (156102), we get a palindrome (357753).

The spelling of 201651 in words is "two hundred one thousand, six hundred fifty-one".