25000021 has 4 divisors (see below), whose sum is σ = 25092544. Its totient is φ = 24907500.

The previous prime is 25000009. The next prime is 25000033. The reversal of 25000021 is 12000052.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (25000009) and next prime (25000033).

It is a cyclic number.

It is not a de Polignac number, because 25000021 - 2¹³ = 24991829 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 24999971 and 25000007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25000321) 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, 45855 + ... + 46396.

It is an arithmetic number, because the mean of its divisors is an integer number (6273136).

Almost surely, 2^25000021 is an apocalyptic number.

It is an amenable number.

25000021 is a deficient number, since it is larger than the sum of its proper divisors (92523).

25000021 is an equidigital number, since it uses as much as digits as its factorization.

25000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92522.

The product of its (nonzero) digits is 20, while the sum is 10.

The square root of 25000021 is about 5000.0020999996. The cubic root of 25000021 is about 292.4018556938.

Adding to 25000021 its reverse (12000052), we get a palindrome (37000073).

The spelling of 25000021 in words is "twenty-five million, twenty-one", and thus it is an aban number and an uban number.