28380511 has 4 divisors (see below), whose sum is σ = 28442272. Its totient is φ = 28318752.

The previous prime is 28380479. The next prime is 28380523. The reversal of 28380511 is 11508382.

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 28380511 - 2⁵ = 28380479 is a prime.

It is a super-2 number, since 2×28380511² = 1610906809242242, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28380511.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28380571) 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, 30186 + ... + 31111.

It is an arithmetic number, because the mean of its divisors is an integer number (7110568).

Almost surely, 2^28380511 is an apocalyptic number.

28380511 is a deficient number, since it is larger than the sum of its proper divisors (61761).

28380511 is an equidigital number, since it uses as much as digits as its factorization.

28380511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61760.

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 28380511 is about 5327.3362011422. The cubic root of 28380511 is about 305.0282550192.

Adding to 28380511 its reverse (11508382), we get a palindrome (39888893).

The spelling of 28380511 in words is "twenty-eight million, three hundred eighty thousand, five hundred eleven".