160999991 has 2 divisors, whose sum is σ = 160999992. Its totient is φ = 160999990.

The previous prime is 160999981. The next prime is 160999999. The reversal of 160999991 is 199999061.

160999991 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 an emirp because it is prime and its reverse (199999061) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-160999991 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (160999999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80499995 + 80499996.

It is an arithmetic number, because the mean of its divisors is an integer number (80499996).

Almost surely, 2^160999991 is an apocalyptic number.

160999991 is a deficient number, since it is larger than the sum of its proper divisors (1).

160999991 is an equidigital number, since it uses as much as digits as its factorization.

160999991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 354294, while the sum is 53.

The square root of 160999991 is about 12688.5771857998. The cubic root of 160999991 is about 544.0121724046.

The spelling of 160999991 in words is "one hundred sixty million, nine hundred ninety-nine thousand, nine hundred ninety-one".