28863691 has 4 divisors (see below), whose sum is σ = 28875400. Its totient is φ = 28851984.

The previous prime is 28863683. The next prime is 28863719. The reversal of 28863691 is 19636882.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 28863691 - 2³ = 28863683 is a prime.

It is a super-2 number, since 2×28863691² = 1666225316286962, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28863661) 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, 561 + ... + 7618.

It is an arithmetic number, because the mean of its divisors is an integer number (7218850).

Almost surely, 2^28863691 is an apocalyptic number.

28863691 is a deficient number, since it is larger than the sum of its proper divisors (11709).

28863691 is an equidigital number, since it uses as much as digits as its factorization.

28863691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11708.

The product of its digits is 124416, while the sum is 43.

The square root of 28863691 is about 5372.4939274047. The cubic root of 28863691 is about 306.7495649917.

The spelling of 28863691 in words is "twenty-eight million, eight hundred sixty-three thousand, six hundred ninety-one".