25221535 has 4 divisors (see below), whose sum is σ = 30265848. Its totient is φ = 20177224.

The previous prime is 25221533. The next prime is 25221541. The reversal of 25221535 is 53512252.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 25221535 - 2¹ = 25221533 is a prime.

It is a super-2 number, since 2×25221535² = 1272251655512450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25221533) 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, 2522149 + ... + 2522158.

It is an arithmetic number, because the mean of its divisors is an integer number (7566462).

Almost surely, 2^25221535 is an apocalyptic number.

25221535 is a deficient number, since it is larger than the sum of its proper divisors (5044313).

25221535 is an equidigital number, since it uses as much as digits as its factorization.

25221535 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5044312.

The product of its digits is 3000, while the sum is 25.

The square root of 25221535 is about 5022.1046384957. The cubic root of 25221535 is about 293.2629314803.

Adding to 25221535 its reverse (53512252), we get a palindrome (78733787).

The spelling of 25221535 in words is "twenty-five million, two hundred twenty-one thousand, five hundred thirty-five".