28123072511 has 4 divisors (see below), whose sum is σ = 29777370912. Its totient is φ = 26468774112.

The previous prime is 28123072507. The next prime is 28123072529. The reversal of 28123072511 is 11527032182.

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 28123072511 - 2² = 28123072507 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 (28123072541) 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, 827149175 + ... + 827149208.

It is an arithmetic number, because the mean of its divisors is an integer number (7444342728).

Almost surely, 2^28123072511 is an apocalyptic number.

28123072511 is a deficient number, since it is larger than the sum of its proper divisors (1654298401).

28123072511 is a wasteful number, since it uses less digits than its factorization.

28123072511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1654298400.

The product of its (nonzero) digits is 6720, while the sum is 32.

The spelling of 28123072511 in words is "twenty-eight billion, one hundred twenty-three million, seventy-two thousand, five hundred eleven".