25122555221 has 4 divisors (see below), whose sum is σ = 25147454700. Its totient is φ = 25097655744.

The previous prime is 25122555083. The next prime is 25122555233. The reversal of 25122555221 is 12255522152.

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

It can be written as a sum of positive squares in 2 ways, for example, as 14413203025 + 10709352196 = 120055^2 + 103486^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25122555221 is a prime.

It is a super-2 number, since 2×25122555221² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25122555721) 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, 12448226 + ... + 12450243.

It is an arithmetic number, because the mean of its divisors is an integer number (6286863675).

Almost surely, 2^25122555221 is an apocalyptic number.

It is an amenable number.

25122555221 is a deficient number, since it is larger than the sum of its proper divisors (24899479).

25122555221 is a wasteful number, since it uses less digits than its factorization.

25122555221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24899478.

The product of its digits is 20000, while the sum is 32.

The spelling of 25122555221 in words is "twenty-five billion, one hundred twenty-two million, five hundred fifty-five thousand, two hundred twenty-one".