28947890 has 16 divisors (see below), whose sum is σ = 52337880. Its totient is φ = 11527680.

The previous prime is 28947883. The next prime is 28947943. The reversal of 28947890 is 9874982.

It can be written as a sum of positive squares in 4 ways, for example, as 19989841 + 8958049 = 4471^2 + 2993^2 .

It is a Curzon number.

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, 4031 + ... + 8610.

Almost surely, 2^28947890 is an apocalyptic number.

28947890 is a deficient number, since it is larger than the sum of its proper divisors (23389990).

28947890 is a wasteful number, since it uses less digits than its factorization.

28947890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12877.

The product of its (nonzero) digits is 290304, while the sum is 47.

The square root of 28947890 is about 5380.3243396658. The cubic root of 28947890 is about 307.0475510524.

The spelling of 28947890 in words is "twenty-eight million, nine hundred forty-seven thousand, eight hundred ninety".