25134821 has 4 divisors (see below), whose sum is σ = 25166700. Its totient is φ = 25102944.

The previous prime is 25134779. The next prime is 25134827. The reversal of 25134821 is 12843152.

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 18576100 + 6558721 = 4310^2 + 2561^2 .

It is a cyclic number.

It is not a de Polignac number, because 25134821 - 2¹⁸ = 24872677 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 (25134827) 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, 14726 + ... + 16343.

It is an arithmetic number, because the mean of its divisors is an integer number (6291675).

Almost surely, 2^25134821 is an apocalyptic number.

It is an amenable number.

25134821 is a deficient number, since it is larger than the sum of its proper divisors (31879).

25134821 is an equidigital number, since it uses as much as digits as its factorization.

25134821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31878.

The product of its digits is 1920, while the sum is 26.

The square root of 25134821 is about 5013.4639721454. The cubic root of 25134821 is about 292.9264570982.

Adding to 25134821 its reverse (12843152), we get a palindrome (37977973).

The spelling of 25134821 in words is "twenty-five million, one hundred thirty-four thousand, eight hundred twenty-one".