2561520 has 80 divisors (see below), whose sum is σ = 8561952. Its totient is φ = 629760.

The previous prime is 2561513. The next prime is 2561521. The reversal of 2561520 is 251652.

2561520 = T₄₁ + T₄₂ + ... + T₂₄₈.

2561520 is digitally balanced in base 2 and base 5, because in such bases it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×2561520² = 13122769420800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2561521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2710 + ... + 3530.

2^2561520 is an apocalyptic number.

2561520 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 2561520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4280976).

2561520 is an abundant number, since it is smaller than the sum of its proper divisors (6000432).

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

2561520 is a wasteful number, since it uses less digits than its factorization.

2561520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 850 (or 844 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 2561520 is about 1600.4749295131. The cubic root of 2561520 is about 136.8251449965.

It can be divided in two parts, 2561 and 520, that added together give a triangular number (3081 = T₇₈).

The spelling of 2561520 in words is "two million, five hundred sixty-one thousand, five hundred twenty".