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28789820 = 2255712521
BaseRepresentation
bin110110111010…
…0110000111100
32000011200012122
41231310300330
524332233240
62505022112
7466465223
oct155646074
960150178
1028789820
1115284244
129784938
135c701c7
143b75cba
1527da4b5
hex1b74c3c

28789820 has 24 divisors (see below), whose sum is σ = 60588528. Its totient is φ = 11491200.

The previous prime is 28789799. The next prime is 28789841. The reversal of 28789820 is 2898782.

It is an interprime number because it is at equal distance from previous prime (28789799) and next prime (28789841).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10160 + ... + 12680.

It is an arithmetic number, because the mean of its divisors is an integer number (2524522).

Almost surely, 228789820 is an apocalyptic number.

28789820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28789820 is an abundant number, since it is smaller than the sum of its proper divisors (31798708).

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

28789820 is a wasteful number, since it uses less digits than its factorization.

28789820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3101 (or 3099 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 44.

The square root of 28789820 is about 5365.6145966702. The cubic root of 28789820 is about 306.4876528215.

The spelling of 28789820 in words is "twenty-eight million, seven hundred eighty-nine thousand, eight hundred twenty".

Divisors: 1 2 4 5 10 20 571 1142 2284 2521 2855 5042 5710 10084 11420 12605 25210 50420 1439491 2878982 5757964 7197455 14394910 28789820