28723081 has 8 divisors (see below), whose sum is σ = 31394304. Its totient is φ = 26160960.

The previous prime is 28723073. The next prime is 28723109. The reversal of 28723081 is 18032782.

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

It is not a de Polignac number, because 28723081 - 2³ = 28723073 is a prime.

It is a super-2 number, since 2×28723081² = 1650030764265122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28723031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26725 + ... + 27778.

It is an arithmetic number, because the mean of its divisors is an integer number (3924288).

Almost surely, 2^28723081 is an apocalyptic number.

It is an amenable number.

28723081 is a deficient number, since it is larger than the sum of its proper divisors (2671223).

28723081 is a wasteful number, since it uses less digits than its factorization.

28723081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54551.

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 28723081 is about 5359.3918498277. The cubic root of 28723081 is about 306.2506418979.

The spelling of 28723081 in words is "twenty-eight million, seven hundred twenty-three thousand, eighty-one".