28263891 has 8 divisors (see below), whose sum is σ = 38324160. Its totient is φ = 18523112.

The previous prime is 28263881. The next prime is 28263931. The reversal of 28263891 is 19836282.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28263891 - 2⁹ = 28263379 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28263881) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 79665 + ... + 80018.

It is an arithmetic number, because the mean of its divisors is an integer number (4790520).

Almost surely, 2^28263891 is an apocalyptic number.

28263891 is a deficient number, since it is larger than the sum of its proper divisors (10060269).

28263891 is a wasteful number, since it uses less digits than its factorization.

28263891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159745.

The product of its digits is 41472, while the sum is 39.

The square root of 28263891 is about 5316.3795011267. The cubic root of 28263891 is about 304.6098783518.

The spelling of 28263891 in words is "twenty-eight million, two hundred sixty-three thousand, eight hundred ninety-one".