25740672721 has 9 divisors (see below), whose sum is σ = 26068023579. Its totient is φ = 25417388136.

The previous prime is 25740672707. The next prime is 25740672733. The reversal of 25740672721 is 12727604752.

The square root of 25740672721 is 160439.

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., 17525788225 + 8214884496 = 132385^2 + 90636^2 .

It is not a de Polignac number, because 25740672721 - 2⁷ = 25740672593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25740672781) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 13315471 + ... + 13317403.

Almost surely, 2^25740672721 is an apocalyptic number.

25740672721 is the 160439-th square number.

25740672721 is the 80220-th centered octagonal number.

It is an amenable number.

25740672721 is a deficient number, since it is larger than the sum of its proper divisors (327350858).

25740672721 is an frugal number, since it uses more digits than its factorization.

25740672721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4032 (or 2016 counting only the distinct ones).

The product of its (nonzero) digits is 329280, while the sum is 43.

The spelling of 25740672721 in words is "twenty-five billion, seven hundred forty million, six hundred seventy-two thousand, seven hundred twenty-one".