2561616 has 30 divisors (see below), whose sum is σ = 7169370. Its totient is φ = 853824.

The previous prime is 2561593. The next prime is 2561627. The reversal of 2561616 is 6161652.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 2547216 + 14400 = 1596^2 + 120^2 .

It is an alternating number because its digits alternate between even and odd.

2561616 is a modest number, since divided by 1616 gives 256 as remainder.

It is a self number, because there is not a number n which added to its sum of digits gives 2561616.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8751 + ... + 9038.

It is an arithmetic number, because the mean of its divisors is an integer number (238979).

2^2561616 is an apocalyptic number.

It is an amenable number.

2561616 is an abundant number, since it is smaller than the sum of its proper divisors (4607754).

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

2561616 is a wasteful number, since it uses less digits than its factorization.

2561616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17803 (or 17794 counting only the distinct ones).

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

The square root of 2561616 is about 1600.5049203298. The cubic root of 2561616 is about 136.8268542746.

The spelling of 2561616 in words is "two million, five hundred sixty-one thousand, six hundred sixteen".