25561606519 has 4 divisors (see below), whose sum is σ = 25561967040. Its totient is φ = 25561246000.

The previous prime is 25561606493. The next prime is 25561606537. The reversal of 25561606519 is 91560616552.

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

It is a cyclic number.

It is not a de Polignac number, because 25561606519 - 2²⁵ = 25528052087 is a prime.

It is a super-2 number, since 2×25561606519² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25561606559) 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, 34759 + ... + 228760.

It is an arithmetic number, because the mean of its divisors is an integer number (6390491760).

Almost surely, 2^25561606519 is an apocalyptic number.

25561606519 is a deficient number, since it is larger than the sum of its proper divisors (360521).

25561606519 is an equidigital number, since it uses as much as digits as its factorization.

25561606519 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 360520.

The product of its (nonzero) digits is 486000, while the sum is 46.

The spelling of 25561606519 in words is "twenty-five billion, five hundred sixty-one million, six hundred six thousand, five hundred nineteen".