161959393 has 4 divisors (see below), whose sum is σ = 162174100. Its totient is φ = 161744688.

The previous prime is 161959349. The next prime is 161959409. The reversal of 161959393 is 393959161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 393959161 = 1181 ⋅333581.

It can be written as a sum of positive squares in 2 ways, for example, as 115283169 + 46676224 = 10737^2 + 6832^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161959393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161959793) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106218 + ... + 107731.

It is an arithmetic number, because the mean of its divisors is an integer number (40543525).

Almost surely, 2^161959393 is an apocalyptic number.

It is an amenable number.

161959393 is a deficient number, since it is larger than the sum of its proper divisors (214707).

161959393 is an equidigital number, since it uses as much as digits as its factorization.

161959393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214706.

The product of its digits is 196830, while the sum is 46.

The square root of 161959393 is about 12726.3267677677. The cubic root of 161959393 is about 545.0906260089.

The spelling of 161959393 in words is "one hundred sixty-one million, nine hundred fifty-nine thousand, three hundred ninety-three".