28744220 has 24 divisors (see below), whose sum is σ = 62445600. Its totient is φ = 11100992.

The previous prime is 28744217. The next prime is 28744231. The reversal of 28744220 is 2244782.

28744220 = T₇₆₉ + T₇₇₀ + ... + T₈₅₅.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24200 + ... + 25359.

It is an arithmetic number, because the mean of its divisors is an integer number (2601900).

Almost surely, 2^28744220 is an apocalyptic number.

28744220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28744220 is an abundant number, since it is smaller than the sum of its proper divisors (33701380).

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

28744220 is a wasteful number, since it uses less digits than its factorization.

28744220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49597 (or 49595 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 29.

The square root of 28744220 is about 5361.3636325099. The cubic root of 28744220 is about 306.3257527447.

The spelling of 28744220 in words is "twenty-eight million, seven hundred forty-four thousand, two hundred twenty".