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68642885 = 513728577
BaseRepresentation
bin1000001011101…
…10100001000101
311210011102100002
410011312201011
5120033033020
610451131045
71462312013
oct405664105
9153142302
1068642885
1135824463
121aba3a85
13112b4bbc
14918b8b3
15605d975
hex4176845

68642885 has 4 divisors (see below), whose sum is σ = 82371468. Its totient is φ = 54914304.

The previous prime is 68642857. The next prime is 68642887. The reversal of 68642885 is 58824686.

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 14737921 + 53904964 = 3839^2 + 7342^2 .

It is a cyclic number.

It is not a de Polignac number, because 68642885 - 224 = 51865669 is a prime.

It is a super-2 number, since 2×686428852 = 9423691322246450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68642887) 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, 6864284 + ... + 6864293.

It is an arithmetic number, because the mean of its divisors is an integer number (20592867).

Almost surely, 268642885 is an apocalyptic number.

It is an amenable number.

68642885 is a deficient number, since it is larger than the sum of its proper divisors (13728583).

68642885 is a wasteful number, since it uses less digits than its factorization.

68642885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13728582.

The product of its digits is 737280, while the sum is 47.

The square root of 68642885 is about 8285.1001804444. The cubic root of 68642885 is about 409.4477693222.

The spelling of 68642885 in words is "sixty-eight million, six hundred forty-two thousand, eight hundred eighty-five".

Divisors: 1 5 13728577 68642885