25551215 has 4 divisors (see below), whose sum is σ = 30661464. Its totient is φ = 20440968.

The previous prime is 25551193. The next prime is 25551217. The reversal of 25551215 is 51215552.

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 25551215 - 2¹⁰ = 25550191 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 (25551217) 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, 2555117 + ... + 2555126.

It is an arithmetic number, because the mean of its divisors is an integer number (7665366).

Almost surely, 2^25551215 is an apocalyptic number.

25551215 is a deficient number, since it is larger than the sum of its proper divisors (5110249).

25551215 is an equidigital number, since it uses as much as digits as its factorization.

25551215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5110248.

The product of its digits is 2500, while the sum is 26.

The square root of 25551215 is about 5054.8209661669. The cubic root of 25551215 is about 294.5351868046.

Adding to 25551215 its reverse (51215552), we get a palindrome (76766767).

The spelling of 25551215 in words is "twenty-five million, five hundred fifty-one thousand, two hundred fifteen".