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138257281 = 197276699
BaseRepresentation
bin10000011110110…
…10001110000001
3100122011012100001
420033122032001
5240343213111
621415200001
73266111311
oct1017321601
9318135301
10138257281
1171051818
123a376001
132284a056
141450d441
15c2101c1
hex83da381

138257281 has 4 divisors (see below), whose sum is σ = 145534000. Its totient is φ = 130980564.

The previous prime is 138257263. The next prime is 138257321. The reversal of 138257281 is 182752831.

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 138257281 - 225 = 104702849 is a prime.

It is a super-2 number, since 2×1382572812 = 38230151499025922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138257281.

It is not an unprimeable number, because it can be changed into a prime (138257881) 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, 3638331 + ... + 3638368.

It is an arithmetic number, because the mean of its divisors is an integer number (36383500).

Almost surely, 2138257281 is an apocalyptic number.

It is an amenable number.

138257281 is a deficient number, since it is larger than the sum of its proper divisors (7276719).

138257281 is an equidigital number, since it uses as much as digits as its factorization.

138257281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7276718.

The product of its digits is 26880, while the sum is 37.

The square root of 138257281 is about 11758.2856318428. The cubic root of 138257281 is about 517.0858703036.

The spelling of 138257281 in words is "one hundred thirty-eight million, two hundred fifty-seven thousand, two hundred eighty-one".

Divisors: 1 19 7276699 138257281