28791906 has 64 divisors (see below), whose sum is σ = 70640640. Its totient is φ = 7698240.

The previous prime is 28791869. The next prime is 28791907. The reversal of 28791906 is 60919782.

It is a super-2 number, since 2×28791906² = 1657947702225672, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28791907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19005 + ... + 20463.

It is an arithmetic number, because the mean of its divisors is an integer number (1103760).

Almost surely, 2^28791906 is an apocalyptic number.

28791906 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 28791906, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35320320).

28791906 is an abundant number, since it is smaller than the sum of its proper divisors (41848734).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28791906 is a wasteful number, since it uses less digits than its factorization.

28791906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1511.

The product of its (nonzero) digits is 54432, while the sum is 42.

The square root of 28791906 is about 5365.8089790823. The cubic root of 28791906 is about 306.4950549496.

The spelling of 28791906 in words is "twenty-eight million, seven hundred ninety-one thousand, nine hundred six".