2561646 has 8 divisors (see below), whose sum is σ = 5123304. Its totient is φ = 853880.

The previous prime is 2561633. The next prime is 2561651. The reversal of 2561646 is 6461652.

It is a sphenic number, since it is the product of 3 distinct primes.

2561646 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 213465 + ... + 213476.

It is an arithmetic number, because the mean of its divisors is an integer number (640413).

2^2561646 is an apocalyptic number.

2561646 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

2561646 is a wasteful number, since it uses less digits than its factorization.

2561646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 426946.

The product of its digits is 8640, while the sum is 30.

The square root of 2561646 is about 1600.5142923448. The cubic root of 2561646 is about 136.8273884152.

The spelling of 2561646 in words is "two million, five hundred sixty-one thousand, six hundred forty-six".