28810581 has 8 divisors (see below), whose sum is σ = 38458464. Its totient is φ = 19184880.

The previous prime is 28810567. The next prime is 28810609. The reversal of 28810581 is 18501882.

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

It is not a de Polignac number, because 28810581 - 2¹⁷ = 28679509 is a prime.

It is a super-2 number, since 2×28810581² = 1660099155115122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28810081) 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, 2230 + ... + 7911.

It is an arithmetic number, because the mean of its divisors is an integer number (4807308).

Almost surely, 2^28810581 is an apocalyptic number.

It is an amenable number.

28810581 is a deficient number, since it is larger than the sum of its proper divisors (9647883).

28810581 is a wasteful number, since it uses less digits than its factorization.

28810581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11091.

The product of its (nonzero) digits is 5120, while the sum is 33.

The square root of 28810581 is about 5367.5488819386. The cubic root of 28810581 is about 306.5613068802.

The spelling of 28810581 in words is "twenty-eight million, eight hundred ten thousand, five hundred eighty-one".