28787690 has 8 divisors (see below), whose sum is σ = 51817860. Its totient is φ = 11515072.

The previous prime is 28787657. The next prime is 28787701. The reversal of 28787690 is 9678782.

It can be written as a sum of positive squares in 2 ways, for example, as 28761769 + 25921 = 5363^2 + 161^2 .

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

It is a super-2 number, since 2×28787690² = 1657462191072200, which contains 22 as substring.

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, 1439375 + ... + 1439394.

Almost surely, 2^28787690 is an apocalyptic number.

28787690 is a deficient number, since it is larger than the sum of its proper divisors (23030170).

28787690 is a wasteful number, since it uses less digits than its factorization.

28787690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2878776.

The product of its (nonzero) digits is 338688, while the sum is 47.

The square root of 28787690 is about 5365.4161068830. The cubic root of 28787690 is about 306.4800941914.

The spelling of 28787690 in words is "twenty-eight million, seven hundred eighty-seven thousand, six hundred ninety".