25223721 has 4 divisors (see below), whose sum is σ = 33631632. Its totient is φ = 16815812.

The previous prime is 25223713. The next prime is 25223741. The reversal of 25223721 is 12732252.

It is a happy number.

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 25223721 - 2³ = 25223713 is a prime.

It is a super-2 number, since 2×25223721² = 1272472202171682, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 25223691 and 25223700.

It is not an unprimeable number, because it can be changed into a prime (25223701) 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, 4203951 + ... + 4203956.

It is an arithmetic number, because the mean of its divisors is an integer number (8407908).

Almost surely, 2^25223721 is an apocalyptic number.

It is an amenable number.

25223721 is a deficient number, since it is larger than the sum of its proper divisors (8407911).

25223721 is an equidigital number, since it uses as much as digits as its factorization.

25223721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8407910.

The product of its digits is 1680, while the sum is 24.

The square root of 25223721 is about 5022.3222716190. The cubic root of 25223721 is about 293.2714037937.

Adding to 25223721 its reverse (12732252), we get a palindrome (37955973).

The spelling of 25223721 in words is "twenty-five million, two hundred twenty-three thousand, seven hundred twenty-one".