25397840689 has 45 divisors (see below), whose sum is σ = 29481172679. Its totient is φ = 21877901760.

The previous prime is 25397840687. The next prime is 25397840701. The reversal of 25397840689 is 98604879352.

The square root of 25397840689 is 159367.

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

It can be written as a sum of positive squares in 7 ways, for example, as 18233911089 + 7163929600 = 135033^2 + 84640^2 .

It is not a de Polignac number, because 25397840689 - 2¹ = 25397840687 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25397840681) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 619459509 + ... + 619459549.

Almost surely, 2^25397840689 is an apocalyptic number.

25397840689 is the 159367-th square number.

25397840689 is the 79684-th centered octagonal number.

It is an amenable number.

25397840689 is a deficient number, since it is larger than the sum of its proper divisors (4083331990).

25397840689 is an frugal number, since it uses more digits than its factorization.

25397840689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180 (or 77 counting only the distinct ones).

The product of its (nonzero) digits is 26127360, while the sum is 61.

The spelling of 25397840689 in words is "twenty-five billion, three hundred ninety-seven million, eight hundred forty thousand, six hundred eighty-nine".