28505100111 has 4 divisors (see below), whose sum is σ = 38006800152. Its totient is φ = 19003400072.

The previous prime is 28505100073. The next prime is 28505100119. The reversal of 28505100111 is 11100150582.

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 28505100111 - 2¹⁵ = 28505067343 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28505100119) 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, 4750850016 + ... + 4750850021.

It is an arithmetic number, because the mean of its divisors is an integer number (9501700038).

Almost surely, 2^28505100111 is an apocalyptic number.

28505100111 is a deficient number, since it is larger than the sum of its proper divisors (9501700041).

28505100111 is an equidigital number, since it uses as much as digits as its factorization.

28505100111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9501700040.

The product of its (nonzero) digits is 400, while the sum is 24.

Adding to 28505100111 its reverse (11100150582), we get a palindrome (39605250693).

The spelling of 28505100111 in words is "twenty-eight billion, five hundred five million, one hundred thousand, one hundred eleven".