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208812381 = 369604127
BaseRepresentation
bin11000111001000…
…11100101011101
3112112220202201220
430130203211131
5411423444011
632415323553
75113606311
oct1434434535
9475822656
10208812381
11a7961918
1259b205b9
133435142b
141da37b41
15134ea506
hexc72395d

208812381 has 4 divisors (see below), whose sum is σ = 278416512. Its totient is φ = 139208252.

The previous prime is 208812379. The next prime is 208812403. The reversal of 208812381 is 183218802.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 208812381 - 21 = 208812379 is a prime.

It is a super-2 number, since 2×2088123812 = 87205220917778322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (208812301) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34802061 + ... + 34802066.

It is an arithmetic number, because the mean of its divisors is an integer number (69604128).

Almost surely, 2208812381 is an apocalyptic number.

It is an amenable number.

208812381 is a deficient number, since it is larger than the sum of its proper divisors (69604131).

208812381 is an equidigital number, since it uses as much as digits as its factorization.

208812381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69604130.

The product of its (nonzero) digits is 6144, while the sum is 33.

The square root of 208812381 is about 14450.3418990694. The cubic root of 208812381 is about 593.2695819720.

The spelling of 208812381 in words is "two hundred eight million, eight hundred twelve thousand, three hundred eighty-one".

Divisors: 1 3 69604127 208812381