28323581 has 32 divisors (see below), whose sum is σ = 35997696. Its totient is φ = 21888000.

The previous prime is 28323577. The next prime is 28323629. The reversal of 28323581 is 18532382.

28323581 = T₉₃₃ + T₉₃₄ + ... + T₉₉₃.

It is a cyclic number.

It is not a de Polignac number, because 28323581 - 2² = 28323577 is a prime.

It is a super-2 number, since 2×28323581² = 1604450481327122, which contains 22 as substring.

It is a Smith number, since the sum of its digits (32) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28323551) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 148196 + ... + 148386.

It is an arithmetic number, because the mean of its divisors is an integer number (1124928).

Almost surely, 2^28323581 is an apocalyptic number.

It is an amenable number.

28323581 is a deficient number, since it is larger than the sum of its proper divisors (7674115).

28323581 is a wasteful number, since it uses less digits than its factorization.

28323581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 293.

The product of its digits is 11520, while the sum is 32.

The square root of 28323581 is about 5321.9903231780. The cubic root of 28323581 is about 304.8241609396.

The spelling of 28323581 in words is "twenty-eight million, three hundred twenty-three thousand, five hundred eighty-one".