28943880 has 64 divisors (see below), whose sum is σ = 99239040. Its totient is φ = 6615552.

The previous prime is 28943861. The next prime is 28943899. The reversal of 28943880 is 8834982.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (28943861) and next prime (28943899).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16389 + ... + 18068.

It is an arithmetic number, because the mean of its divisors is an integer number (1550610).

Almost surely, 2^28943880 is an apocalyptic number.

28943880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28943880 is an abundant number, since it is smaller than the sum of its proper divisors (70295160).

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

28943880 is a wasteful number, since it uses less digits than its factorization.

28943880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34478 (or 34474 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 42.

The square root of 28943880 is about 5379.9516726454. The cubic root of 28943880 is about 307.0333724999.

The spelling of 28943880 in words is "twenty-eight million, nine hundred forty-three thousand, eight hundred eighty".