28944381 has 4 divisors (see below), whose sum is σ = 38592512. Its totient is φ = 19296252.

The previous prime is 28944371. The next prime is 28944437. The reversal of 28944381 is 18344982.

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 not a de Polignac number, because 28944381 - 2¹⁰ = 28943357 is a prime.

It is a super-2 number, since 2×28944381² = 1675554382946322, 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 (28944361) 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, 4824061 + ... + 4824066.

It is an arithmetic number, because the mean of its divisors is an integer number (9648128).

Almost surely, 2^28944381 is an apocalyptic number.

It is an amenable number.

28944381 is a deficient number, since it is larger than the sum of its proper divisors (9648131).

28944381 is an equidigital number, since it uses as much as digits as its factorization.

28944381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9648130.

The product of its digits is 55296, while the sum is 39.

The square root of 28944381 is about 5379.9982342005. The cubic root of 28944381 is about 307.0351440066.

The spelling of 28944381 in words is "twenty-eight million, nine hundred forty-four thousand, three hundred eighty-one".