2561166 has 32 divisors (see below), whose sum is σ = 5829120. Its totient is φ = 833112.

The previous prime is 2561159. The next prime is 2561179. The reversal of 2561166 is 6611652.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1771 + ... + 2873.

It is an arithmetic number, because the mean of its divisors is an integer number (182160).

2^2561166 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2561166, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2914560).

2561166 is an abundant number, since it is smaller than the sum of its proper divisors (3267954).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2561166 is a wasteful number, since it uses less digits than its factorization.

2561166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1157 (or 1151 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 2561166 is about 1600.3643335191. The cubic root of 2561166 is about 136.8188416646.

The spelling of 2561166 in words is "two million, five hundred sixty-one thousand, one hundred sixty-six".