161999711 has 2 divisors, whose sum is σ = 161999712. Its totient is φ = 161999710.

The previous prime is 161999699. The next prime is 161999743. The reversal of 161999711 is 117999161.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161999711 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161999011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80999855 + 80999856.

It is an arithmetic number, because the mean of its divisors is an integer number (80999856).

Almost surely, 2^161999711 is an apocalyptic number.

161999711 is a deficient number, since it is larger than the sum of its proper divisors (1).

161999711 is an equidigital number, since it uses as much as digits as its factorization.

161999711 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30618, while the sum is 44.

The square root of 161999711 is about 12727.9107083606. The cubic root of 161999711 is about 545.1358536841.

The spelling of 161999711 in words is "one hundred sixty-one million, nine hundred ninety-nine thousand, seven hundred eleven".