25023759721 has 3 divisors (see below), whose sum is σ = 25023917911. Its totient is φ = 25023601532.

The previous prime is 25023759707. The next prime is 25023759727. The reversal of 25023759721 is 12795732052.

The square root of 25023759721 is 158189.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 11720444121 + 13303315600 = 108261^2 + 115340^2 .

It is not a de Polignac number, because 25023759721 - 2⁵ = 25023759689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25023759727) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 79095 + ... + 237283.

Almost surely, 2^25023759721 is an apocalyptic number.

25023759721 is the 158189-th square number.

25023759721 is the 79095-th centered octagonal number.

It is an amenable number.

25023759721 is a deficient number, since it is larger than the sum of its proper divisors (158190).

25023759721 is an frugal number, since it uses more digits than its factorization.

25023759721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 316378 (or 158189 counting only the distinct ones).

The product of its (nonzero) digits is 264600, while the sum is 43.

The spelling of 25023759721 in words is "twenty-five billion, twenty-three million, seven hundred fifty-nine thousand, seven hundred twenty-one".