161639 has 2 divisors, whose sum is σ = 161640. Its totient is φ = 161638.
The previous prime is 161627. The next prime is 161641. The reversal of 161639 is 936161.
It is a strong prime.
It is an emirp because it is prime and its reverse (936161) is a distict prime.
It is a cyclic number.
It is not a de Polignac number, because 161639 - 212 = 157543 is a prime.
It is a super-2 number, since 2×1616392 = 52254332642, which contains 22 as substring.
Together with 161641, it forms a pair of twin primes.
It is a Chen prime.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (161659) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80819 + 80820.
It is an arithmetic number, because the mean of its divisors is an integer number (80820).
2161639 is an apocalyptic number.
161639 is a deficient number, since it is larger than the sum of its proper divisors (1).
161639 is an equidigital number, since it uses as much as digits as its factorization.
161639 is an evil number, because the sum of its binary digits is even.
The product of its digits is 972, while the sum is 26.
The square root of 161639 is about 402.0435299815. The cubic root of 161639 is about 54.4730950443.
The spelling of 161639 in words is "one hundred sixty-one thousand, six hundred thirty-nine".
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