25516228644 has 81 divisors (see below), whose sum is σ = 65520559377. Its totient is φ = 8372827008.

The previous prime is 25516228613. The next prime is 25516228649. The reversal of 25516228644 is 44682261552.

The square root of 25516228644 is 159738.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 6880702500 + 18635526144 = 82950^2 + 136512^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 25516228644.

It is not an unprimeable number, because it can be changed into a prime (25516228649) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 75715644 + ... + 75715980.

Almost surely, 2^25516228644 is an apocalyptic number.

25516228644 is the 159738-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25516228644

25516228644 is an abundant number, since it is smaller than the sum of its proper divisors (40004330733).

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

25516228644 is an equidigital number, since it uses as much as digits as its factorization.

25516228644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 842 (or 421 counting only the distinct ones).

The product of its digits is 921600, while the sum is 45.

The spelling of 25516228644 in words is "twenty-five billion, five hundred sixteen million, two hundred twenty-eight thousand, six hundred forty-four".