25121555 has 4 divisors (see below), whose sum is σ = 30145872. Its totient is φ = 20097240.

The previous prime is 25121539. The next prime is 25121581. The reversal of 25121555 is 55512152.

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

It is not a de Polignac number, because 25121555 - 2⁴ = 25121539 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2512151 + ... + 2512160.

It is an arithmetic number, because the mean of its divisors is an integer number (7536468).

Almost surely, 2^25121555 is an apocalyptic number.

25121555 is a deficient number, since it is larger than the sum of its proper divisors (5024317).

25121555 is an equidigital number, since it uses as much as digits as its factorization.

25121555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5024316.

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

The square root of 25121555 is about 5012.1407601942. The cubic root of 25121555 is about 292.8749131168.

The spelling of 25121555 in words is "twenty-five million, one hundred twenty-one thousand, five hundred fifty-five".