25197421 has 4 divisors (see below), whose sum is σ = 25428700. Its totient is φ = 24966144.

The previous prime is 25197391. The next prime is 25197437. The reversal of 25197421 is 12479152.

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 8916196 + 16281225 = 2986^2 + 4035^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25197421 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 (25192421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 115476 + ... + 115693.

It is an arithmetic number, because the mean of its divisors is an integer number (6357175).

Almost surely, 2^25197421 is an apocalyptic number.

It is an amenable number.

25197421 is a deficient number, since it is larger than the sum of its proper divisors (231279).

25197421 is a wasteful number, since it uses less digits than its factorization.

25197421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231278.

The product of its digits is 5040, while the sum is 31.

The square root of 25197421 is about 5019.7032780833. The cubic root of 25197421 is about 293.1694399823.

The spelling of 25197421 in words is "twenty-five million, one hundred ninety-seven thousand, four hundred twenty-one".