28403732 has 18 divisors (see below), whose sum is σ = 57822282. Its totient is φ = 12172944.

The previous prime is 28403729. The next prime is 28403741. The reversal of 28403732 is 23730482.

It can be written as a sum of positive squares in only one way, i.e., 27415696 + 988036 = 5236^2 + 994^2 .

It is a junction number, because it is equal to n+sod(n) for n = 28403695 and 28403704.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 72263 + ... + 72654.

It is an arithmetic number, because the mean of its divisors is an integer number (3212349).

Almost surely, 2^28403732 is an apocalyptic number.

It is an amenable number.

28403732 is an abundant number, since it is smaller than the sum of its proper divisors (29418550).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28403732 is a wasteful number, since it uses less digits than its factorization.

28403732 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144935 (or 144926 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 29.

The square root of 28403732 is about 5329.5151749479. The cubic root of 28403732 is about 305.1114239492. Note that the first 3 decimals are identical.

The spelling of 28403732 in words is "twenty-eight million, four hundred three thousand, seven hundred thirty-two".