28478691 has 12 divisors (see below), whose sum is σ = 41345200. Its totient is φ = 18889200.

The previous prime is 28478683. The next prime is 28478693. The reversal of 28478691 is 19687482.

It is not a de Polignac number, because 28478691 - 2³ = 28478683 is a prime.

It is a super-2 number, since 2×28478691² = 1622071682146962, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28478693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6160 + ... + 9741.

Almost surely, 2^28478691 is an apocalyptic number.

28478691 is a deficient number, since it is larger than the sum of its proper divisors (12866509).

28478691 is a wasteful number, since it uses less digits than its factorization.

28478691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16106 (or 16103 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The square root of 28478691 is about 5336.5429821187. The cubic root of 28478691 is about 305.3795900894.

The spelling of 28478691 in words is "twenty-eight million, four hundred seventy-eight thousand, six hundred ninety-one".