28121766 has 8 divisors (see below), whose sum is σ = 56243544. Its totient is φ = 9373920.

The previous prime is 28121761. The next prime is 28121771. The reversal of 28121766 is 66712182.

It is an interprime number because it is at equal distance from previous prime (28121761) and next prime (28121771).

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

28121766 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28121761) 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 3 ways as a sum of consecutive naturals, for example, 2343475 + ... + 2343486.

It is an arithmetic number, because the mean of its divisors is an integer number (7030443).

Almost surely, 2^28121766 is an apocalyptic number.

28121766 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

28121766 is a wasteful number, since it uses less digits than its factorization.

28121766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4686966.

The product of its digits is 8064, while the sum is 33.

The square root of 28121766 is about 5302.9959456896. The cubic root of 28121766 is about 304.0984431296.

It can be divided in two parts, 2812176 and 6, that added together give a palindrome (2812182).

The spelling of 28121766 in words is "twenty-eight million, one hundred twenty-one thousand, seven hundred sixty-six".