2561171850 has 36 divisors (see below), whose sum is σ = 6881016246. Its totient is φ = 682979040.

The previous prime is 2561171849. The next prime is 2561171867. The reversal of 2561171850 is 581711652.

2561171850 is a `hidden beast` number, since 2 + 561 + 17 + 1 + 85 + 0 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 2382708969 + 178462881 = 48813^2 + 13359^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 2845297 + ... + 2846196.

Almost surely, 2^2561171850 is an apocalyptic number.

2561171850 is an abundant number, since it is smaller than the sum of its proper divisors (4319844396).

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

2561171850 is a wasteful number, since it uses less digits than its factorization.

2561171850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5691511 (or 5691503 counting only the distinct ones).

The product of its (nonzero) digits is 16800, while the sum is 36.

The square root of 2561171850 is about 50608.0215973713. The cubic root of 2561171850 is about 1368.1894583451.

It can be divided in two parts, 25611 and 71850, that added together give a triangular number (97461 = T₄₄₁).

The spelling of 2561171850 in words is "two billion, five hundred sixty-one million, one hundred seventy-one thousand, eight hundred fifty".