161743381 has 2 divisors, whose sum is σ = 161743382. Its totient is φ = 161743380.

The previous prime is 161743363. The next prime is 161743459. The reversal of 161743381 is 183347161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 161036100 + 707281 = 12690^2 + 841^2 .

It is a cyclic number.

It is not a de Polignac number, because 161743381 - 2⁹ = 161742869 is a prime.

It is a super-2 number, since 2×161743381² = 52321842594622322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161743781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80871690 + 80871691.

It is an arithmetic number, because the mean of its divisors is an integer number (80871691).

Almost surely, 2^161743381 is an apocalyptic number.

It is an amenable number.

161743381 is a deficient number, since it is larger than the sum of its proper divisors (1).

161743381 is an equidigital number, since it uses as much as digits as its factorization.

161743381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 34.

The square root of 161743381 is about 12717.8371195734. The cubic root of 161743381 is about 544.8481814871.

The spelling of 161743381 in words is "one hundred sixty-one million, seven hundred forty-three thousand, three hundred eighty-one".