161957867 has 4 divisors (see below), whose sum is σ = 164612976. Its totient is φ = 159302760.

The previous prime is 161957833. The next prime is 161957897. The reversal of 161957867 is 768759161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 768759161 = 3769 ⋅203969.

It is a cyclic number.

It is not a de Polignac number, because 161957867 - 2⁸ = 161957611 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161957897) 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 in 3 ways as a sum of consecutive naturals, for example, 1327463 + ... + 1327584.

It is an arithmetic number, because the mean of its divisors is an integer number (41153244).

Almost surely, 2^161957867 is an apocalyptic number.

161957867 is a deficient number, since it is larger than the sum of its proper divisors (2655109).

161957867 is an equidigital number, since it uses as much as digits as its factorization.

161957867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2655108.

The product of its digits is 635040, while the sum is 50.

The square root of 161957867 is about 12726.2668131703. The cubic root of 161957867 is about 545.0889140347.

The spelling of 161957867 in words is "one hundred sixty-one million, nine hundred fifty-seven thousand, eight hundred sixty-seven".