28641840 has 80 divisors (see below), whose sum is σ = 89565696. Its totient is φ = 7571200.

The previous prime is 28641793. The next prime is 28641853. The reversal of 28641840 is 4814682.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30985 + ... + 31895.

Almost surely, 2^28641840 is an apocalyptic number.

28641840 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 28641840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44782848).

28641840 is an abundant number, since it is smaller than the sum of its proper divisors (60923856).

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

28641840 is a wasteful number, since it uses less digits than its factorization.

28641840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1058 (or 1052 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 33.

The square root of 28641840 is about 5351.8071714142. The cubic root of 28641840 is about 305.9616338759.

The spelling of 28641840 in words is "twenty-eight million, six hundred forty-one thousand, eight hundred forty".