25511 has 4 divisors (see below), whose sum is σ = 25872. Its totient is φ = 25152.

The previous prime is 25471. The next prime is 25523. The reversal of 25511 is 11552.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 25511 - 2⁶ = 25447 is a prime.

It is a super-2 number, since 2×25511² = 1301622242, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

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 3 ways as a sum of consecutive naturals, for example, 35 + ... + 228.

It is an arithmetic number, because the mean of its divisors is an integer number (6468).

2²⁵⁵¹¹ is an apocalyptic number.

25511 is a deficient number, since it is larger than the sum of its proper divisors (361).

25511 is an equidigital number, since it uses as much as digits as its factorization.

25511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360.

The product of its digits is 50, while the sum is 14.

The square root of 25511 is about 159.7216328492. The cubic root of 25511 is about 29.4380582909.

It can be divided in two parts, 2551 and 1, that added together give a palindrome (2552).

The spelling of 25511 in words is "twenty-five thousand, five hundred eleven".