161939473 has 2 divisors, whose sum is σ = 161939474. Its totient is φ = 161939472.

The previous prime is 161939441. The next prime is 161939537. The reversal of 161939473 is 374939161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 111344704 + 50594769 = 10552^2 + 7113^2 .

It is a cyclic number.

It is not a de Polignac number, because 161939473 - 2⁵ = 161939441 is a prime.

It is not a weakly prime, because it can be changed into another prime (161939273) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80969736 + 80969737.

It is an arithmetic number, because the mean of its divisors is an integer number (80969737).

Almost surely, 2^161939473 is an apocalyptic number.

It is an amenable number.

161939473 is a deficient number, since it is larger than the sum of its proper divisors (1).

161939473 is an equidigital number, since it uses as much as digits as its factorization.

161939473 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 122472, while the sum is 43.

The square root of 161939473 is about 12725.5441141037. The cubic root of 161939473 is about 545.0682775048.

The spelling of 161939473 in words is "one hundred sixty-one million, nine hundred thirty-nine thousand, four hundred seventy-three".