25551 has 12 divisors (see below), whose sum is σ = 39312. Its totient is φ = 15936.

The previous prime is 25541. The next prime is 25561. The reversal of 25551 is 15552.

It is an interprime number because it is at equal distance from previous prime (25541) and next prime (25561).

It is not a de Polignac number, because 25551 - 2⁷ = 25423 is a prime.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25541) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 70 + ... + 236.

It is an arithmetic number, because the mean of its divisors is an integer number (3276).

2²⁵⁵⁵¹ is an apocalyptic number.

25551 is a deficient number, since it is larger than the sum of its proper divisors (13761).

25551 is a wasteful number, since it uses less digits than its factorization.

25551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190 (or 187 counting only the distinct ones).

The product of its digits is 250, while the sum is 18.

The square root of 25551 is about 159.8468016571. The cubic root of 25551 is about 29.4534360683.

Subtracting from 25551 its reverse (15552), we obtain a palindrome (9999).

It can be divided in two parts, 2555 and 1, that added together give a triangular number (2556 = T₇₁).

The spelling of 25551 in words is "twenty-five thousand, five hundred fifty-one".