28644880 has 80 divisors (see below), whose sum is σ = 74441664. Its totient is φ = 10160640.

The previous prime is 28644829. The next prime is 28644883. The reversal of 28644880 is 8844682.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-5 number, since 5×28644880⁵ (a number of 38 digits) contains 55555 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (28644883) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37462 + ... + 38218.

Almost surely, 2^28644880 is an apocalyptic number.

28644880 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 28644880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37220832).

28644880 is an abundant number, since it is smaller than the sum of its proper divisors (45796784).

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

28644880 is a wasteful number, since it uses less digits than its factorization.

28644880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 824 (or 818 counting only the distinct ones).

The product of its (nonzero) digits is 98304, while the sum is 40.

The square root of 28644880 is about 5352.0911800903. The cubic root of 28644880 is about 305.9724582556.

It can be divided in two parts, 2864 and 4880, that added together give a square (7744 = 88²).

The spelling of 28644880 in words is "twenty-eight million, six hundred forty-four thousand, eight hundred eighty".