28231776 has 72 divisors (see below), whose sum is σ = 81651024. Its totient is φ = 9250560.

The previous prime is 28231769. The next prime is 28231817. The reversal of 28231776 is 67713282.

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×28231776² = 1594066352228352, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 28231776.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16765 + ... + 18371.

It is an arithmetic number, because the mean of its divisors is an integer number (1134042).

Almost surely, 2^28231776 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28231776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40825512).

28231776 is an abundant number, since it is smaller than the sum of its proper divisors (53419248).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28231776 is a wasteful number, since it uses less digits than its factorization.

28231776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1684 (or 1673 counting only the distinct ones).

The product of its digits is 28224, while the sum is 36.

The square root of 28231776 is about 5313.3582600837. The cubic root of 28231776 is about 304.4944630829.

The spelling of 28231776 in words is "twenty-eight million, two hundred thirty-one thousand, seven hundred seventy-six".