28441981 has 2 divisors, whose sum is σ = 28441982. Its totient is φ = 28441980.

The previous prime is 28441967. The next prime is 28442009. The reversal of 28441981 is 18914482.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18576100 + 9865881 = 4310^2 + 3141^2 .

It is a cyclic number.

It is not a de Polignac number, because 28441981 - 2⁵ = 28441949 is a prime.

It is a super-2 number, since 2×28441981² = 1617892566408722, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28441981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28441951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14220990 + 14220991.

It is an arithmetic number, because the mean of its divisors is an integer number (14220991).

Almost surely, 2^28441981 is an apocalyptic number.

It is an amenable number.

28441981 is a deficient number, since it is larger than the sum of its proper divisors (1).

28441981 is an equidigital number, since it uses as much as digits as its factorization.

28441981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18432, while the sum is 37.

The square root of 28441981 is about 5333.1023804161. The cubic root of 28441981 is about 305.2483187808.

The spelling of 28441981 in words is "twenty-eight million, four hundred forty-one thousand, nine hundred eighty-one".