161742901 has 2 divisors, whose sum is σ = 161742902. Its totient is φ = 161742900.

The previous prime is 161742881. The next prime is 161742937. The reversal of 161742901 is 109247161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 105042001 + 56700900 = 10249^2 + 7530^2 .

It is an emirp because it is prime and its reverse (109247161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161742901 - 2⁵ = 161742869 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161742001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80871450 + 80871451.

It is an arithmetic number, because the mean of its divisors is an integer number (80871451).

Almost surely, 2^161742901 is an apocalyptic number.

It is an amenable number.

161742901 is a deficient number, since it is larger than the sum of its proper divisors (1).

161742901 is an equidigital number, since it uses as much as digits as its factorization.

161742901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 161742901 is about 12717.8182484261. The cubic root of 161742901 is about 544.8476425111.

The spelling of 161742901 in words is "one hundred sixty-one million, seven hundred forty-two thousand, nine hundred one".