28777784 has 32 divisors (see below), whose sum is σ = 64350720. Its totient is φ = 11796576.

The previous prime is 28777783. The next prime is 28777811. The reversal of 28777784 is 48777782.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28777783) 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, 9884 + ... + 12459.

It is an arithmetic number, because the mean of its divisors is an integer number (2010960).

Almost surely, 2^28777784 is an apocalyptic number.

It is an amenable number.

28777784 is an abundant number, since it is smaller than the sum of its proper divisors (35572936).

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

28777784 is a wasteful number, since it uses less digits than its factorization.

28777784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22379 (or 22375 counting only the distinct ones).

The product of its digits is 1229312, while the sum is 50.

The square root of 28777784 is about 5364.4928930888. The cubic root of 28777784 is about 306.4449363385. Note that the first 3 decimals are identical.

It can be divided in two parts, 2877778 and 4, that added together give a palindrome (2877782).

The spelling of 28777784 in words is "twenty-eight million, seven hundred seventy-seven thousand, seven hundred eighty-four".