28820290 has 8 divisors (see below), whose sum is σ = 51876540. Its totient is φ = 11528112.

The previous prime is 28820269. The next prime is 28820291. The reversal of 28820290 is 9202882.

It can be written as a sum of positive squares in 2 ways, for example, as 28291761 + 528529 = 5319^2 + 727^2 .

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

It is not an unprimeable number, because it can be changed into a prime (28820291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1441005 + ... + 1441024.

Almost surely, 2^28820290 is an apocalyptic number.

28820290 is a deficient number, since it is larger than the sum of its proper divisors (23056250).

28820290 is a wasteful number, since it uses less digits than its factorization.

28820290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2882036.

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 28820290 is about 5368.4532222978. The cubic root of 28820290 is about 306.5957394780.

The spelling of 28820290 in words is "twenty-eight million, eight hundred twenty thousand, two hundred ninety".