161461381 has 2 divisors, whose sum is σ = 161461382. Its totient is φ = 161461380.

The previous prime is 161461379. The next prime is 161461387. The reversal of 161461381 is 183164161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 140209281 + 21252100 = 11841^2 + 4610^2 .

It is a cyclic number.

It is not a de Polignac number, because 161461381 - 2¹ = 161461379 is a prime.

It is a super-2 number, since 2×161461381² = 52139555108854322, which contains 22 as substring.

Together with 161461379, 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 (161461387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80730690 + 80730691.

It is an arithmetic number, because the mean of its divisors is an integer number (80730691).

Almost surely, 2^161461381 is an apocalyptic number.

It is an amenable number.

161461381 is a deficient number, since it is larger than the sum of its proper divisors (1).

161461381 is an equidigital number, since it uses as much as digits as its factorization.

161461381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3456, while the sum is 31.

The square root of 161461381 is about 12706.7454920605. The cubic root of 161461381 is about 544.5313492153.

The spelling of 161461381 in words is "one hundred sixty-one million, four hundred sixty-one thousand, three hundred eighty-one".