28820311 has 16 divisors (see below), whose sum is σ = 32711616. Its totient is φ = 25191936.

The previous prime is 28820291. The next prime is 28820347. The reversal of 28820311 is 11302882.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28820311 is a prime.

It is a super-2 number, since 2×28820311² = 1661220652273442, 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 (28820381) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33361 + ... + 34213.

It is an arithmetic number, because the mean of its divisors is an integer number (2044476).

Almost surely, 2^28820311 is an apocalyptic number.

28820311 is a deficient number, since it is larger than the sum of its proper divisors (3891305).

28820311 is a wasteful number, since it uses less digits than its factorization.

28820311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1002.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 28820311 is about 5368.4551781681. The cubic root of 28820311 is about 306.5958139454.

The spelling of 28820311 in words is "twenty-eight million, eight hundred twenty thousand, three hundred eleven".