28772111 has 4 divisors (see below), whose sum is σ = 29177424. Its totient is φ = 28366800.

The previous prime is 28772077. The next prime is 28772141. The reversal of 28772111 is 11127782.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28772111 - 2¹⁸ = 28509967 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28772141) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 202550 + ... + 202691.

It is an arithmetic number, because the mean of its divisors is an integer number (7294356).

Almost surely, 2^28772111 is an apocalyptic number.

28772111 is a deficient number, since it is larger than the sum of its proper divisors (405313).

28772111 is an equidigital number, since it uses as much as digits as its factorization.

28772111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405312.

The product of its digits is 1568, while the sum is 29.

The square root of 28772111 is about 5363.9641124825. The cubic root of 28772111 is about 306.4247983926.

Adding to 28772111 its reverse (11127782), we get a palindrome (39899893).

The spelling of 28772111 in words is "twenty-eight million, seven hundred seventy-two thousand, one hundred eleven".