28187069 has 4 divisors (see below), whose sum is σ = 28235196. Its totient is φ = 28138944.

The previous prime is 28187057. The next prime is 28187077. The reversal of 28187069 is 96078182.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 24900100 + 3286969 = 4990^2 + 1813^2 .

It is a cyclic number.

It is not a de Polignac number, because 28187069 - 2⁸ = 28186813 is a prime.

It is a super-2 number, since 2×28187069² = 1589021717621522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28187009) 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, 23174 + ... + 24359.

It is an arithmetic number, because the mean of its divisors is an integer number (7058799).

Almost surely, 2^28187069 is an apocalyptic number.

It is an amenable number.

28187069 is a deficient number, since it is larger than the sum of its proper divisors (48127).

28187069 is an equidigital number, since it uses as much as digits as its factorization.

28187069 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48126.

The product of its (nonzero) digits is 48384, while the sum is 41.

The square root of 28187069 is about 5309.1495552489. The cubic root of 28187069 is about 304.3336487105. Note that the first 3 decimals are identical.

The spelling of 28187069 in words is "twenty-eight million, one hundred eighty-seven thousand, sixty-nine".