28399786 has 8 divisors (see below), whose sum is σ = 43021764. Its totient is φ = 14059200.

The previous prime is 28399783. The next prime is 28399799. The reversal of 28399786 is 68799382.

It can be written as a sum of positive squares in 2 ways, for example, as 20385225 + 8014561 = 4515^2 + 2831^2 .

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 (28399783) 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, 70095 + ... + 70498.

Almost surely, 2^28399786 is an apocalyptic number.

28399786 is a deficient number, since it is larger than the sum of its proper divisors (14621978).

28399786 is a wasteful number, since it uses less digits than its factorization.

28399786 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140696.

The product of its digits is 1306368, while the sum is 52.

The square root of 28399786 is about 5329.1449595596. The cubic root of 28399786 is about 305.0972940520.

The spelling of 28399786 in words is "twenty-eight million, three hundred ninety-nine thousand, seven hundred eighty-six".