28721110 has 16 divisors (see below), whose sum is σ = 56398032. Its totient is φ = 10444000.

The previous prime is 28721093. The next prime is 28721113. The reversal of 28721110 is 1112782.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28721113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 130441 + ... + 130660.

It is an arithmetic number, because the mean of its divisors is an integer number (3524877).

Almost surely, 2^28721110 is an apocalyptic number.

28721110 is a deficient number, since it is larger than the sum of its proper divisors (27676922).

28721110 is a wasteful number, since it uses less digits than its factorization.

28721110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261119.

The product of its (nonzero) digits is 224, while the sum is 22.

The square root of 28721110 is about 5359.2079638693. The cubic root of 28721110 is about 306.2436366858.

Adding to 28721110 its reverse (1112782), we get a palindrome (29833892).

The spelling of 28721110 in words is "twenty-eight million, seven hundred twenty-one thousand, one hundred ten".