25651 has 4 divisors (see below), whose sum is σ = 25992. Its totient is φ = 25312.

The previous prime is 25643. The next prime is 25657. The reversal of 25651 is 15652.

It is a happy number.

25651 is a nontrivial binomial coefficient, being equal to C(227, 2).

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 is not a de Polignac number, because 25651 - 2³ = 25643 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (25657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1 + ... + 226.

It is an arithmetic number, because the mean of its divisors is an integer number (6498).

2²⁵⁶⁵¹ is an apocalyptic number.

25651 is the 226-th triangular number.

25651 is the 76-th centered nonagonal number.

25651 is a deficient number, since it is larger than the sum of its proper divisors (341).

25651 is a wasteful number, since it uses less digits than its factorization.

25651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340.

The product of its digits is 300, while the sum is 19.

The square root of 25651 is about 160.1592957027. The cubic root of 25651 is about 29.4918104242.

Subtracting from 25651 its reverse (15652), we obtain a palindrome (9999).

It can be divided in two parts, 25 and 651, that added together give a palindrome (676).

The spelling of 25651 in words is "twenty-five thousand, six hundred fifty-one".