28208690 has 8 divisors (see below), whose sum is σ = 50775660. Its totient is φ = 11283472.

The previous prime is 28208683. The next prime is 28208699. The reversal of 28208690 is 9680282.

It can be written as a sum of positive squares in 2 ways, for example, as 23512801 + 4695889 = 4849^2 + 2167^2 .

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

It is a super-2 number, since 2×28208690² = 1591460383032200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28208690.

It is not an unprimeable number, because it can be changed into a prime (28208699) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1410425 + ... + 1410444.

Almost surely, 2^28208690 is an apocalyptic number.

28208690 is a deficient number, since it is larger than the sum of its proper divisors (22566970).

28208690 is a wasteful number, since it uses less digits than its factorization.

28208690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2820876.

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 28208690 is about 5311.1853667519. The cubic root of 28208690 is about 304.4114422563.

The spelling of 28208690 in words is "twenty-eight million, two hundred eight thousand, six hundred ninety".