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686621 = 1352817
BaseRepresentation
bin10100111101000011101
31021212212102
42213220131
5133432441
622414445
75556545
oct2475035
91255772
10686621
11429961
12291425
131b06b0
1413c325
15d869b
hexa7a1d

686621 has 4 divisors (see below), whose sum is σ = 739452. Its totient is φ = 633792.

The previous prime is 686611. The next prime is 686639. The reversal of 686621 is 126686.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 28900 + 657721 = 170^2 + 811^2 .

It is a cyclic number.

It is not a de Polignac number, because 686621 - 214 = 670237 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686611) 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 3 ways as a sum of consecutive naturals, for example, 26396 + ... + 26421.

It is an arithmetic number, because the mean of its divisors is an integer number (184863).

2686621 is an apocalyptic number.

It is an amenable number.

686621 is a deficient number, since it is larger than the sum of its proper divisors (52831).

686621 is a wasteful number, since it uses less digits than its factorization.

686621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52830.

The product of its digits is 3456, while the sum is 29.

The square root of 686621 is about 828.6259711112. The cubic root of 686621 is about 88.2210780844.

The spelling of 686621 in words is "six hundred eighty-six thousand, six hundred twenty-one".

Divisors: 1 13 52817 686621