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28380205 = 571942677
BaseRepresentation
bin110110001000…
…0110000101101
31222101212022201
41230100300231
524231131310
62452141501
7463141060
oct154206055
958355281
1028380205
1115024517
129607891
135b58929
143aaa8d7
152758e3a
hex1b10c2d

28380205 has 16 divisors (see below), whose sum is σ = 40970880. Its totient is φ = 18436032.

The previous prime is 28380203. The next prime is 28380211. The reversal of 28380205 is 50208382.

It is a cyclic number.

It is not a de Polignac number, because 28380205 - 21 = 28380203 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28380203) by changing a digit.

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, 20674 + ... + 22003.

It is an arithmetic number, because the mean of its divisors is an integer number (2560680).

Almost surely, 228380205 is an apocalyptic number.

It is an amenable number.

28380205 is a deficient number, since it is larger than the sum of its proper divisors (12590675).

28380205 is a wasteful number, since it uses less digits than its factorization.

28380205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42708.

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 28380205 is about 5327.3074812704. The cubic root of 28380205 is about 305.0271587390.

Adding to 28380205 its reverse (50208382), we get a palindrome (78588587).

The spelling of 28380205 in words is "twenty-eight million, three hundred eighty thousand, two hundred five".

Divisors: 1 5 7 19 35 95 133 665 42677 213385 298739 810863 1493695 4054315 5676041 28380205