25511591 has 4 divisors (see below), whose sum is σ = 29156112. Its totient is φ = 21867072.

The previous prime is 25511581. The next prime is 25511593. The reversal of 25511591 is 19511552.

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 25511591 - 2⁶ = 25511527 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25511593) 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, 1822250 + ... + 1822263.

It is an arithmetic number, because the mean of its divisors is an integer number (7289028).

Almost surely, 2^25511591 is an apocalyptic number.

25511591 is a deficient number, since it is larger than the sum of its proper divisors (3644521).

25511591 is an equidigital number, since it uses as much as digits as its factorization.

25511591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3644520.

The product of its digits is 2250, while the sum is 29.

The square root of 25511591 is about 5050.9000188085. The cubic root of 25511591 is about 294.3828561454.

The spelling of 25511591 in words is "twenty-five million, five hundred eleven thousand, five hundred ninety-one".