25828021 has 4 divisors (see below), whose sum is σ = 25840044. Its totient is φ = 25816000.

The previous prime is 25828003. The next prime is 25828039. The reversal of 25828021 is 12082852.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is an interprime number because it is at equal distance from previous prime (25828003) and next prime (25828039).

It can be written as a sum of positive squares in 2 ways, for example, as 19140625 + 6687396 = 4375^2 + 2586^2 .

It is a cyclic number.

It is not a de Polignac number, because 25828021 - 2¹¹ = 25825973 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 (25828001) 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, 1810 + ... + 7411.

It is an arithmetic number, because the mean of its divisors is an integer number (6460011).

Almost surely, 2^25828021 is an apocalyptic number.

It is an amenable number.

25828021 is a deficient number, since it is larger than the sum of its proper divisors (12023).

25828021 is an equidigital number, since it uses as much as digits as its factorization.

25828021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12022.

The product of its (nonzero) digits is 2560, while the sum is 28.

The square root of 25828021 is about 5082.1276056392. The cubic root of 25828021 is about 295.5949727319.

The spelling of 25828021 in words is "twenty-five million, eight hundred twenty-eight thousand, twenty-one".