28981930 has 16 divisors (see below), whose sum is σ = 52237224. Its totient is φ = 11577280.

The previous prime is 28981907. The next prime is 28981943. The reversal of 28981930 is 3918982.

It can be written as a sum of positive squares in 4 ways, for example, as 13935289 + 15046641 = 3733^2 + 3879^2 .

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, 8700 + ... + 11560.

Almost surely, 2^28981930 is an apocalyptic number.

28981930 is a deficient number, since it is larger than the sum of its proper divisors (23255294).

28981930 is a wasteful number, since it uses less digits than its factorization.

28981930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3881.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 28981930 is about 5383.4867883185. The cubic root of 28981930 is about 307.1678569365.

The spelling of 28981930 in words is "twenty-eight million, nine hundred eighty-one thousand, nine hundred thirty".