161923291 has 2 divisors, whose sum is σ = 161923292. Its totient is φ = 161923290.

The previous prime is 161923273. The next prime is 161923303. The reversal of 161923291 is 192329161.

161923291 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 161923291 - 2⁵ = 161923259 is a prime.

It is a super-3 number, since 3×161923291³ (a number of 26 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (161924291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80961645 + 80961646.

It is an arithmetic number, because the mean of its divisors is an integer number (80961646).

Almost surely, 2^161923291 is an apocalyptic number.

161923291 is a deficient number, since it is larger than the sum of its proper divisors (1).

161923291 is an equidigital number, since it uses as much as digits as its factorization.

161923291 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5832, while the sum is 34.

The square root of 161923291 is about 12724.9082904357. The cubic root of 161923291 is about 545.0501213618.

The spelling of 161923291 in words is "one hundred sixty-one million, nine hundred twenty-three thousand, two hundred ninety-one".