2561513513 has 4 divisors (see below), whose sum is σ = 2758553028. Its totient is φ = 2364474000.

The previous prime is 2561513503. The next prime is 2561513533. The reversal of 2561513513 is 3153151652.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1498231849 + 1063281664 = 38707^2 + 32608^2 .

It is a cyclic number.

It is not a de Polignac number, because 2561513513 - 2¹⁰ = 2561512489 is a prime.

It is a super-2 number, since 2×2561513513² = 13122702954563202338, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2561513513.

It is not an unprimeable number, because it can be changed into a prime (2561513503) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 98519738 + ... + 98519763.

It is an arithmetic number, because the mean of its divisors is an integer number (689638257).

Almost surely, 2^2561513513 is an apocalyptic number.

It is an amenable number.

2561513513 is a deficient number, since it is larger than the sum of its proper divisors (197039515).

2561513513 is a wasteful number, since it uses less digits than its factorization.

2561513513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197039514.

The product of its digits is 13500, while the sum is 32.

The square root of 2561513513 is about 50611.3970662735. The cubic root of 2561513513 is about 1368.2502949410.

The spelling of 2561513513 in words is "two billion, five hundred sixty-one million, five hundred thirteen thousand, five hundred thirteen".