161155811 has 2 divisors, whose sum is σ = 161155812. Its totient is φ = 161155810.

The previous prime is 161155781. The next prime is 161155817. The reversal of 161155811 is 118551161.

161155811 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 161155811 - 2¹⁰ = 161154787 is a prime.

It is not a weakly prime, because it can be changed into another prime (161155817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80577905 + 80577906.

It is an arithmetic number, because the mean of its divisors is an integer number (80577906).

Almost surely, 2^161155811 is an apocalyptic number.

161155811 is a deficient number, since it is larger than the sum of its proper divisors (1).

161155811 is an equidigital number, since it uses as much as digits as its factorization.

161155811 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1200, while the sum is 29.

The square root of 161155811 is about 12694.7158692111. The cubic root of 161155811 is about 544.1876188834.

The spelling of 161155811 in words is "one hundred sixty-one million, one hundred fifty-five thousand, eight hundred eleven".