28169919 has 6 divisors (see below), whose sum is σ = 40689896. Its totient is φ = 18779940.

The previous prime is 28169903. The next prime is 28169971. The reversal of 28169919 is 91996182.

It is not a de Polignac number, because 28169919 - 2⁴ = 28169903 is a prime.

It is a super-2 number, since 2×28169919² = 1587088672933122, 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 (28169719) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1564987 + ... + 1565004.

Almost surely, 2^28169919 is an apocalyptic number.

28169919 is a deficient number, since it is larger than the sum of its proper divisors (12519977).

28169919 is a wasteful number, since it uses less digits than its factorization.

28169919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3129997 (or 3129994 counting only the distinct ones).

The product of its digits is 69984, while the sum is 45.

The square root of 28169919 is about 5307.5341732296. The cubic root of 28169919 is about 304.2719137713.

The spelling of 28169919 in words is "twenty-eight million, one hundred sixty-nine thousand, nine hundred nineteen".