161973401 has 2 divisors, whose sum is σ = 161973402. Its totient is φ = 161973400.

The previous prime is 161973379. The next prime is 161973437. The reversal of 161973401 is 104379161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 102313225 + 59660176 = 10115^2 + 7724^2 .

It is a cyclic number.

It is not a de Polignac number, because 161973401 - 2²⁶ = 94864537 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (161973451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80986700 + 80986701.

It is an arithmetic number, because the mean of its divisors is an integer number (80986701).

Almost surely, 2^161973401 is an apocalyptic number.

It is an amenable number.

161973401 is a deficient number, since it is larger than the sum of its proper divisors (1).

161973401 is an equidigital number, since it uses as much as digits as its factorization.

161973401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 161973401 is about 12726.8771110591. The cubic root of 161973401 is about 545.1063406668.

The spelling of 161973401 in words is "one hundred sixty-one million, nine hundred seventy-three thousand, four hundred one".