25557551 has 4 divisors (see below), whose sum is σ = 25654992. Its totient is φ = 25460112.

The previous prime is 25557541. The next prime is 25557563. The reversal of 25557551 is 15575552.

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 25557551 - 2¹⁰ = 25556527 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 (25557541) 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, 48326 + ... + 48851.

It is an arithmetic number, because the mean of its divisors is an integer number (6413748).

Almost surely, 2^25557551 is an apocalyptic number.

25557551 is a deficient number, since it is larger than the sum of its proper divisors (97441).

25557551 is an equidigital number, since it uses as much as digits as its factorization.

25557551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97440.

The product of its digits is 43750, while the sum is 35.

The square root of 25557551 is about 5055.4476557472. The cubic root of 25557551 is about 294.5595303399.

The spelling of 25557551 in words is "twenty-five million, five hundred fifty-seven thousand, five hundred fifty-one".