28121768 has 16 divisors (see below), whose sum is σ = 52852500. Its totient is φ = 14027776.

The previous prime is 28121761. The next prime is 28121771. The reversal of 28121768 is 86712182.

It can be written as a sum of positive squares in 2 ways, for example, as 27478564 + 643204 = 5242^2 + 802^2 .

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 polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 323 + ... + 7506.

Almost surely, 2^28121768 is an apocalyptic number.

It is an amenable number.

28121768 is a deficient number, since it is larger than the sum of its proper divisors (24730732).

28121768 is a wasteful number, since it uses less digits than its factorization.

28121768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8284 (or 8280 counting only the distinct ones).

The product of its digits is 10752, while the sum is 35.

The square root of 28121768 is about 5302.9961342622. The cubic root of 28121768 is about 304.0984503387.

The spelling of 28121768 in words is "twenty-eight million, one hundred twenty-one thousand, seven hundred sixty-eight".