25500021 has 4 divisors (see below), whose sum is σ = 34000032. Its totient is φ = 17000012.

The previous prime is 25500001. The next prime is 25500023. The reversal of 25500021 is 12000552.

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 a cyclic number.

It is not a de Polignac number, because 25500021 - 2¹¹ = 25497973 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25500023) 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, 4250001 + ... + 4250006.

It is an arithmetic number, because the mean of its divisors is an integer number (8500008).

Almost surely, 2^25500021 is an apocalyptic number.

It is an amenable number.

25500021 is a deficient number, since it is larger than the sum of its proper divisors (8500011).

25500021 is an equidigital number, since it uses as much as digits as its factorization.

25500021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8500010.

The product of its (nonzero) digits is 100, while the sum is 15.

The square root of 25500021 is about 5049.7545484905. The cubic root of 25500021 is about 294.3383466429.

Adding to 25500021 its reverse (12000552), we get a palindrome (37500573).

The spelling of 25500021 in words is "twenty-five million, five hundred thousand, twenty-one".