28182781 has 8 divisors (see below), whose sum is σ = 30875328. Its totient is φ = 25512000.

The previous prime is 28182769. The next prime is 28182823. The reversal of 28182781 is 18728182.

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

It is a cyclic number.

It is not a de Polignac number, because 28182781 - 2⁷ = 28182653 is a prime.

It is a super-2 number, since 2×28182781² = 1588538289787922, 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 28182781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28182881) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2665 + ... + 7966.

It is an arithmetic number, because the mean of its divisors is an integer number (3859416).

Almost surely, 2^28182781 is an apocalyptic number.

It is an amenable number.

28182781 is a deficient number, since it is larger than the sum of its proper divisors (2692547).

28182781 is a wasteful number, since it uses less digits than its factorization.

28182781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10883.

The product of its digits is 14336, while the sum is 37.

The square root of 28182781 is about 5308.7457087338. The cubic root of 28182781 is about 304.3182155241.

The spelling of 28182781 in words is "twenty-eight million, one hundred eighty-two thousand, seven hundred eighty-one".