201556171 has 4 divisors (see below), whose sum is σ = 201888832. Its totient is φ = 201223512.

The previous prime is 201556133. The next prime is 201556189. The reversal of 201556171 is 171655102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 171655102 = 2 ⋅85827551.

It is a cyclic number.

It is not a de Polignac number, because 201556171 - 2⁹ = 201555659 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (201550171) 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, 165420 + ... + 166633.

It is an arithmetic number, because the mean of its divisors is an integer number (50472208).

Almost surely, 2^201556171 is an apocalyptic number.

201556171 is a deficient number, since it is larger than the sum of its proper divisors (332661).

201556171 is an equidigital number, since it uses as much as digits as its factorization.

201556171 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332660.

The product of its (nonzero) digits is 2100, while the sum is 28.

The square root of 201556171 is about 14197.0479677995. The cubic root of 201556171 is about 586.3163878732.

The spelling of 201556171 in words is "two hundred one million, five hundred fifty-six thousand, one hundred seventy-one".