28081930 has 8 divisors (see below), whose sum is σ = 50547492. Its totient is φ = 11232768.

The previous prime is 28081913. The next prime is 28081951. The reversal of 28081930 is 3918082.

It can be written as a sum of positive squares in 2 ways, for example, as 23068809 + 5013121 = 4803^2 + 2239^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 28081892 and 28081901.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1404087 + ... + 1404106.

Almost surely, 2^28081930 is an apocalyptic number.

28081930 is a deficient number, since it is larger than the sum of its proper divisors (22465562).

28081930 is a wasteful number, since it uses less digits than its factorization.

28081930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2808200.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 28081930 is about 5299.2386245573. The cubic root of 28081930 is about 303.9547846534.

The spelling of 28081930 in words is "twenty-eight million, eighty-one thousand, nine hundred thirty".