28669840 has 20 divisors (see below), whose sum is σ = 66657564. Its totient is φ = 11467904.

The previous prime is 28669831. The next prime is 28669843. The reversal of 28669840 is 4896682.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 19501056 + 9168784 = 4416^2 + 3028^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (28669843) 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, 179107 + ... + 179266.

Almost surely, 2^28669840 is an apocalyptic number.

28669840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28669840 is an abundant number, since it is smaller than the sum of its proper divisors (37987724).

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

28669840 is a wasteful number, since it uses less digits than its factorization.

28669840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 358386 (or 358380 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 43.

The square root of 28669840 is about 5354.4224711915. The cubic root of 28669840 is about 306.0613031664.

The spelling of 28669840 in words is "twenty-eight million, six hundred sixty-nine thousand, eight hundred forty".