25221881 has 4 divisors (see below), whose sum is σ = 25294500. Its totient is φ = 25149264.

The previous prime is 25221871. The next prime is 25221899. The reversal of 25221881 is 18812252.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 13388281 + 11833600 = 3659^2 + 3440^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25221881 is a prime.

It is a super-2 number, since 2×25221881² = 1272286562356322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25221841) 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, 35786 + ... + 36483.

It is an arithmetic number, because the mean of its divisors is an integer number (6323625).

Almost surely, 2^25221881 is an apocalyptic number.

It is an amenable number.

25221881 is a deficient number, since it is larger than the sum of its proper divisors (72619).

25221881 is an equidigital number, since it uses as much as digits as its factorization.

25221881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72618.

The product of its digits is 2560, while the sum is 29.

The square root of 25221881 is about 5022.1390860867. The cubic root of 25221881 is about 293.2642725103.

The spelling of 25221881 in words is "twenty-five million, two hundred twenty-one thousand, eight hundred eighty-one".