28415881 has 8 divisors (see below), whose sum is σ = 30661064. Its totient is φ = 26179200.

The previous prime is 28415867. The next prime is 28415899. The reversal of 28415881 is 18851482.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 156025 + 28259856 = 395^2 + 5316^2 .

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 28415881 - 2⁷ = 28415753 is a prime.

It is a super-2 number, since 2×28415881² = 1614924586012322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28415881.

It is not an unprimeable number, because it can be changed into a prime (28416881) 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, 5995 + ... + 9631.

It is an arithmetic number, because the mean of its divisors is an integer number (3832633).

Almost surely, 2^28415881 is an apocalyptic number.

It is an amenable number.

28415881 is a deficient number, since it is larger than the sum of its proper divisors (2245183).

28415881 is a wasteful number, since it uses less digits than its factorization.

28415881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4251.

The product of its digits is 20480, while the sum is 37.

The square root of 28415881 is about 5330.6548378225. The cubic root of 28415881 is about 305.1549190589.

The spelling of 28415881 in words is "twenty-eight million, four hundred fifteen thousand, eight hundred eighty-one".