161906539 has 2 divisors, whose sum is σ = 161906540. Its totient is φ = 161906538.

The previous prime is 161906519. The next prime is 161906551. The reversal of 161906539 is 935609161.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 161906539 - 2⁷ = 161906411 is a prime.

It is not a weakly prime, because it can be changed into another prime (161906509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80953269 + 80953270.

It is an arithmetic number, because the mean of its divisors is an integer number (80953270).

Almost surely, 2^161906539 is an apocalyptic number.

161906539 is a deficient number, since it is larger than the sum of its proper divisors (1).

161906539 is an equidigital number, since it uses as much as digits as its factorization.

161906539 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 43740, while the sum is 40.

The square root of 161906539 is about 12724.2500368391. The cubic root of 161906539 is about 545.0313244067.

The spelling of 161906539 in words is "one hundred sixty-one million, nine hundred six thousand, five hundred thirty-nine".