2561536 has 20 divisors (see below), whose sum is σ = 5119092. Its totient is φ = 1280512.

The previous prime is 2561527. The next prime is 2561549. The reversal of 2561536 is 6351652.

It is a super-2 number, since 2×2561536² = 13122933358592, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1990 + ... + 3013.

2^2561536 is an apocalyptic number.

It is an amenable number.

2561536 is a deficient number, since it is larger than the sum of its proper divisors (2557556).

2561536 is an frugal number, since it uses more digits than its factorization.

2561536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5021 (or 5005 counting only the distinct ones).

The product of its digits is 5400, while the sum is 28.

The square root of 2561536 is about 1600.4799280216. The cubic root of 2561536 is about 136.8254298792.

It can be divided in two parts, 25615 and 36, that added together give a triangular number (25651 = T₂₂₆).

The spelling of 2561536 in words is "two million, five hundred sixty-one thousand, five hundred thirty-six".