28881645 has 32 divisors (see below), whose sum is σ = 51123072. Its totient is φ = 13830912.

The previous prime is 28881617. The next prime is 28881649. The reversal of 28881645 is 54618882.

It is not a de Polignac number, because 28881645 - 2⁹ = 28881133 is a prime.

It is a super-3 number, since 3×28881645³ (a number of 23 digits) contains 333 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 28881597 and 28881606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28881649) 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, 5214 + ... + 9216.

It is an arithmetic number, because the mean of its divisors is an integer number (1597596).

Almost surely, 2^28881645 is an apocalyptic number.

It is an amenable number.

28881645 is a deficient number, since it is larger than the sum of its proper divisors (22241427).

28881645 is a wasteful number, since it uses less digits than its factorization.

28881645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4061.

The product of its digits is 122880, while the sum is 42.

The square root of 28881645 is about 5374.1645862404. The cubic root of 28881645 is about 306.8131539967.

The spelling of 28881645 in words is "twenty-eight million, eight hundred eighty-one thousand, six hundred forty-five".