161899841 has 2 divisors, whose sum is σ = 161899842. Its totient is φ = 161899840.

The previous prime is 161899831. The next prime is 161899849. The reversal of 161899841 is 148998161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 160554241 + 1345600 = 12671^2 + 1160^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161899841 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (161899849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80949920 + 80949921.

It is an arithmetic number, because the mean of its divisors is an integer number (80949921).

Almost surely, 2^161899841 is an apocalyptic number.

It is an amenable number.

161899841 is a deficient number, since it is larger than the sum of its proper divisors (1).

161899841 is an equidigital number, since it uses as much as digits as its factorization.

161899841 is an evil number, because the sum of its binary digits is even.

The product of its digits is 124416, while the sum is 47.

The square root of 161899841 is about 12723.9868358939. The cubic root of 161899841 is about 545.0238084036.

The spelling of 161899841 in words is "one hundred sixty-one million, eight hundred ninety-nine thousand, eight hundred forty-one".