28808993 has 2 divisors, whose sum is σ = 28808994. Its totient is φ = 28808992.

The previous prime is 28808987. The next prime is 28809007. The reversal of 28808993 is 39980882.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18421264 + 10387729 = 4292^2 + 3223^2 .

It is a cyclic number.

It is not a de Polignac number, because 28808993 - 2¹⁰ = 28807969 is a prime.

It is not a weakly prime, because it can be changed into another prime (28808953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14404496 + 14404497.

It is an arithmetic number, because the mean of its divisors is an integer number (14404497).

Almost surely, 2^28808993 is an apocalyptic number.

It is an amenable number.

28808993 is a deficient number, since it is larger than the sum of its proper divisors (1).

28808993 is an equidigital number, since it uses as much as digits as its factorization.

28808993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 248832, while the sum is 47.

The square root of 28808993 is about 5367.4009539068. The cubic root of 28808993 is about 306.5556743628. Note that the first 3 decimals are identical.

The spelling of 28808993 in words is "twenty-eight million, eight hundred eight thousand, nine hundred ninety-three".