161672891 has 2 divisors, whose sum is σ = 161672892. Its totient is φ = 161672890.

The previous prime is 161672857. The next prime is 161672899. The reversal of 161672891 is 198276161.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 161672891 - 2¹⁸ = 161410747 is a prime.

It is a super-2 number, since 2×161672891² = 52276247368595762, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (161672899) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80836445 + 80836446.

It is an arithmetic number, because the mean of its divisors is an integer number (80836446).

Almost surely, 2^161672891 is an apocalyptic number.

161672891 is a deficient number, since it is larger than the sum of its proper divisors (1).

161672891 is an equidigital number, since it uses as much as digits as its factorization.

161672891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 41.

The square root of 161672891 is about 12715.0655130046. The cubic root of 161672891 is about 544.7690191977.

The spelling of 161672891 in words is "one hundred sixty-one million, six hundred seventy-two thousand, eight hundred ninety-one".