28555511 has 4 divisors (see below), whose sum is σ = 28773624. Its totient is φ = 28337400.

The previous prime is 28555463. The next prime is 28555519. The reversal of 28555511 is 11555582.

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 28555511 - 2⁶ = 28555447 is a prime.

It is a super-2 number, since 2×28555511² = 1630834416942242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28555519) 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 3 ways as a sum of consecutive naturals, for example, 108860 + ... + 109121.

It is an arithmetic number, because the mean of its divisors is an integer number (7193406).

Almost surely, 2^28555511 is an apocalyptic number.

28555511 is a deficient number, since it is larger than the sum of its proper divisors (218113).

28555511 is a wasteful number, since it uses less digits than its factorization.

28555511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218112.

The product of its digits is 10000, while the sum is 32.

The square root of 28555511 is about 5343.7356783434. The cubic root of 28555511 is about 305.6539261796.

The spelling of 28555511 in words is "twenty-eight million, five hundred fifty-five thousand, five hundred eleven".