2561900 has 72 divisors (see below), whose sum is σ = 6468336. Its totient is φ = 870400.

The previous prime is 2561899. The next prime is 2561921. The reversal of 2561900 is 91652.

2561900 = T₄₅₀ + T₄₅₁ + ... + T₄₇₃.

It is a super-2 number, since 2×2561900² = 13126663220000, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18632 + ... + 18768.

It is an arithmetic number, because the mean of its divisors is an integer number (89838).

2^2561900 is an apocalyptic number.

2561900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2561900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3234168).

2561900 is an abundant number, since it is smaller than the sum of its proper divisors (3906436).

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

2561900 is a wasteful number, since it uses less digits than its factorization.

2561900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179 (or 172 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 2561900 is about 1600.5936398724. The cubic root of 2561900 is about 136.8319106388.

The spelling of 2561900 in words is "two million, five hundred sixty-one thousand, nine hundred".