155801 has 2 divisors, whose sum is σ = 155802. Its totient is φ = 155800.
The previous prime is 155797. The next prime is 155809. The reversal of 155801 is 108551.
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 105625 + 50176 = 325^2 + 224^2 .
It is a cyclic number.
It is not a de Polignac number, because 155801 - 22 = 155797 is a prime.
It is a Sophie Germain prime.
It is a Chen prime.
It is a Curzon number.
It is not a weakly prime, because it can be changed into another prime (155809) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (7) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77900 + 77901.
It is an arithmetic number, because the mean of its divisors is an integer number (77901).
2155801 is an apocalyptic number.
It is an amenable number.
155801 is a deficient number, since it is larger than the sum of its proper divisors (1).
155801 is an equidigital number, since it uses as much as digits as its factorization.
155801 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 200, while the sum is 20.
The square root of 155801 is about 394.7163538543. The cubic root of 155801 is about 53.8092262246.
The spelling of 155801 in words is "one hundred fifty-five thousand, eight hundred one".
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