28388769 has 16 divisors (see below), whose sum is σ = 38937024. Its totient is φ = 18387200.

The previous prime is 28388741. The next prime is 28388791. The reversal of 28388769 is 96788382.

It is a cyclic number.

It is not a de Polignac number, because 28388769 - 2⁸ = 28388513 is a prime.

It is a super-2 number, since 2×28388769² = 1611844410670722, which contains 22 as substring.

Its product of digits (1161216) is a multiple of the sum of its prime divisors (1008).

It is not an unprimeable number, because it can be changed into a prime (28388669) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54229 + ... + 54749.

It is an arithmetic number, because the mean of its divisors is an integer number (2433564).

Almost surely, 2^28388769 is an apocalyptic number.

It is an amenable number.

28388769 is a deficient number, since it is larger than the sum of its proper divisors (10548255).

28388769 is a wasteful number, since it uses less digits than its factorization.

28388769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1008.

The product of its digits is 1161216, while the sum is 51.

The square root of 28388769 is about 5328.1112037945. Note that the first 3 decimals coincide. The cubic root of 28388769 is about 305.0578372803.

The spelling of 28388769 in words is "twenty-eight million, three hundred eighty-eight thousand, seven hundred sixty-nine".