25650021 has 4 divisors (see below), whose sum is σ = 34200032. Its totient is φ = 17100012.

The previous prime is 25650017. The next prime is 25650029. The reversal of 25650021 is 12005652.

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 not a de Polignac number, because 25650021 - 2² = 25650017 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 25650021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25650029) 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, 4275001 + ... + 4275006.

It is an arithmetic number, because the mean of its divisors is an integer number (8550008).

Almost surely, 2^25650021 is an apocalyptic number.

It is an amenable number.

25650021 is a deficient number, since it is larger than the sum of its proper divisors (8550011).

25650021 is an equidigital number, since it uses as much as digits as its factorization.

25650021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8550010.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 25650021 is about 5064.5849780609. The cubic root of 25650021 is about 294.9143522309.

Adding to 25650021 its reverse (12005652), we get a palindrome (37655673).

The spelling of 25650021 in words is "twenty-five million, six hundred fifty thousand, twenty-one".