28191369 has 16 divisors (see below), whose sum is σ = 38997504. Its totient is φ = 18096000.

The previous prime is 28191349. The next prime is 28191377. The reversal of 28191369 is 96319182.

It is not a de Polignac number, because 28191369 - 2⁵ = 28191337 is a prime.

It is a super-2 number, since 2×28191369² = 1589506572188322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28191329) 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, 21019 + ... + 22319.

It is an arithmetic number, because the mean of its divisors is an integer number (2437344).

Almost surely, 2^28191369 is an apocalyptic number.

It is an amenable number.

28191369 is a deficient number, since it is larger than the sum of its proper divisors (10806135).

28191369 is a wasteful number, since it uses less digits than its factorization.

28191369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1568.

The product of its digits is 23328, while the sum is 39.

The square root of 28191369 is about 5309.5545010858. The cubic root of 28191369 is about 304.3491235150.

The spelling of 28191369 in words is "twenty-eight million, one hundred ninety-one thousand, three hundred sixty-nine".