201556 has 12 divisors (see below), whose sum is σ = 361620. Its totient is φ = 98240.

The previous prime is 201547. The next prime is 201557. The reversal of 201556 is 655102.

201556 = T₂₅ + T₂₆ + ... + T₁₀₆.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 111556 + 90000 = 334^2 + 300^2 .

It is a super-2 number, since 2×201556² = 81249642272, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201557) by changing a digit.

201556 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 451 + ... + 778.

It is an arithmetic number, because the mean of its divisors is an integer number (30135).

2²⁰¹⁵⁵⁶ is an apocalyptic number.

It is an amenable number.

201556 is a deficient number, since it is larger than the sum of its proper divisors (160064).

201556 is a wasteful number, since it uses less digits than its factorization.

201556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1274 (or 1272 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 201556 is about 448.9498858447. The cubic root of 201556 is about 58.6316222063.

Adding to 201556 its reverse (655102), we get a palindrome (856658).

It can be divided in two parts, 201 and 556, that added together give a palindrome (757).

The spelling of 201556 in words is "two hundred one thousand, five hundred fifty-six".