Search a number
-
+
28809900 = 223252717269
BaseRepresentation
bin110110111100…
…1101010101100
32000012200202100
41231321222230
524333404100
62505255100
7466610610
oct155715254
960180670
1028809900
1115298339
129794490
135c793a2
143b7d340
1527e1400
hex1b79aac

28809900 has 216 divisors, whose sum is σ = 109680480. Its totient is φ = 6174720.

The previous prime is 28809887. The next prime is 28809901. The reversal of 28809900 is 990882.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (28809901) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 106966 + ... + 107234.

It is an arithmetic number, because the mean of its divisors is an integer number (507780).

Almost surely, 228809900 is an apocalyptic number.

28809900 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 28809900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (54840240).

28809900 is an abundant number, since it is smaller than the sum of its proper divisors (80870580).

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

28809900 is a wasteful number, since it uses less digits than its factorization.

28809900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313 (or 303 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 28809900 is about 5367.4854447870. The cubic root of 28809900 is about 306.5588914494.

The spelling of 28809900 in words is "twenty-eight million, eight hundred nine thousand, nine hundred".