28021732 has 24 divisors (see below), whose sum is σ = 51830240. Its totient is φ = 13219200.

The previous prime is 28021727. The next prime is 28021757. The reversal of 28021732 is 23712082.

It is a junction number, because it is equal to n+sod(n) for n = 28021697 and 28021706.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22732 + ... + 23932.

Almost surely, 2^28021732 is an apocalyptic number.

It is an amenable number.

28021732 is a deficient number, since it is larger than the sum of its proper divisors (23808508).

28021732 is a wasteful number, since it uses less digits than its factorization.

28021732 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1531 (or 1529 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 28021732 is about 5293.5557048169. Note that the first 3 decimals coincide. The cubic root of 28021732 is about 303.7374377662.

The spelling of 28021732 in words is "twenty-eight million, twenty-one thousand, seven hundred thirty-two".