28121290 has 8 divisors (see below), whose sum is σ = 50618340. Its totient is φ = 11248512.

The previous prime is 28121267. The next prime is 28121321. The reversal of 28121290 is 9212182.

It can be written as a sum of positive squares in 2 ways, for example, as 27952369 + 168921 = 5287^2 + 411^2 .

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

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, 1406055 + ... + 1406074.

Almost surely, 2^28121290 is an apocalyptic number.

28121290 is a deficient number, since it is larger than the sum of its proper divisors (22497050).

28121290 is a wasteful number, since it uses less digits than its factorization.

28121290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2812136.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 28121290 is about 5302.9510652089. The cubic root of 28121290 is about 304.0967273569.

The spelling of 28121290 in words is "twenty-eight million, one hundred twenty-one thousand, two hundred ninety".