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137728 = 29269
BaseRepresentation
bin100001101000000000
320222221001
4201220000
513401403
62541344
71112353
oct415000
9228831
10137728
1194528
1267854
134a8c6
143829a
152ac1d
hex21a00

137728 has 20 divisors (see below), whose sum is σ = 276210. Its totient is φ = 68608.

The previous prime is 137723. The next prime is 137737. The reversal of 137728 is 827731.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 135424 + 2304 = 368^2 + 48^2 .

It is a junction number, because it is equal to n+sod(n) for n = 137696 and 137705.

It is not an unprimeable number, because it can be changed into a prime (137723) by changing a digit.

137728 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 378 + ... + 646.

137728 is a Friedman number, since it can be written as 371^2+87, using all its digits and the basic arithmetic operations.

2137728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 137728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138105).

137728 is an abundant number, since it is smaller than the sum of its proper divisors (138482).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

137728 is an frugal number, since it uses more digits than its factorization.

137728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 287 (or 271 counting only the distinct ones).

The product of its digits is 2352, while the sum is 28.

The square root of 137728 is about 371.1172321518. The cubic root of 137728 is about 51.6425184875.

The spelling of 137728 in words is "one hundred thirty-seven thousand, seven hundred twenty-eight".

Divisors: 1 2 4 8 16 32 64 128 256 269 512 538 1076 2152 4304 8608 17216 34432 68864 137728