28869840 has 120 divisors (see below), whose sum is σ = 98161128. Its totient is φ = 7603200.

The previous prime is 28869833. The next prime is 28869851. The reversal of 28869840 is 4896882.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 12027024 + 16842816 = 3468^2 + 4104^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 72522 + ... + 72918.

Almost surely, 2^28869840 is an apocalyptic number.

28869840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28869840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49080564).

28869840 is an abundant number, since it is smaller than the sum of its proper divisors (69291288).

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

28869840 is a wasteful number, since it uses less digits than its factorization.

28869840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 517 (or 508 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 45.

The square root of 28869840 is about 5373.0661637467. The cubic root of 28869840 is about 306.7713463265.

The spelling of 28869840 in words is "twenty-eight million, eight hundred sixty-nine thousand, eight hundred forty".