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231661 is a prime number
BaseRepresentation
bin111000100011101101
3102202210001
4320203231
524403121
64544301
71653253
oct704355
9382701
10231661
11149061
12b2091
13815a1
14605d3
1548991
hex388ed

231661 has 2 divisors, whose sum is σ = 231662. Its totient is φ = 231660.

The previous prime is 231643. The next prime is 231677. The reversal of 231661 is 166132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 189225 + 42436 = 435^2 + 206^2 .

It is a cyclic number.

It is not a de Polignac number, because 231661 - 27 = 231533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115830 + 115831.

It is an arithmetic number, because the mean of its divisors is an integer number (115831).

2231661 is an apocalyptic number.

It is an amenable number.

231661 is a deficient number, since it is larger than the sum of its proper divisors (1).

231661 is an equidigital number, since it uses as much as digits as its factorization.

231661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 216, while the sum is 19.

The square root of 231661 is about 481.3117492852. The cubic root of 231661 is about 61.4163933210.

Adding to 231661 its reverse (166132), we get a palindrome (397793).

The spelling of 231661 in words is "two hundred thirty-one thousand, six hundred sixty-one".