161543 has 2 divisors, whose sum is σ = 161544. Its totient is φ = 161542.

The previous prime is 161531. The next prime is 161561. The reversal of 161543 is 345161.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 161543 - 2⁴ = 161527 is a prime.

It is a super-2 number, since 2×161543² = 52192281698, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80771 + 80772.

It is an arithmetic number, because the mean of its divisors is an integer number (80772).

2¹⁶¹⁵⁴³ is an apocalyptic number.

161543 is a deficient number, since it is larger than the sum of its proper divisors (1).

161543 is an equidigital number, since it uses as much as digits as its factorization.

161543 is an evil number, because the sum of its binary digits is even.

The product of its digits is 360, while the sum is 20.

The square root of 161543 is about 401.9241221922. The cubic root of 161543 is about 54.4623087597.

The spelling of 161543 in words is "one hundred sixty-one thousand, five hundred forty-three".