161989822 has 4 divisors (see below), whose sum is σ = 242984736. Its totient is φ = 80994910.

The previous prime is 161989819. The next prime is 161989823. The reversal of 161989822 is 228989161.

161989822 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 228989161 = 97 ⋅2360713.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161989823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40497454 + ... + 40497457.

It is an arithmetic number, because the mean of its divisors is an integer number (60746184).

Almost surely, 2^161989822 is an apocalyptic number.

161989822 is a deficient number, since it is larger than the sum of its proper divisors (80994914).

161989822 is an equidigital number, since it uses as much as digits as its factorization.

161989822 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80994913.

The product of its digits is 124416, while the sum is 46.

The square root of 161989822 is about 12727.5222254766. The cubic root of 161989822 is about 545.1247611578.

The spelling of 161989822 in words is "one hundred sixty-one million, nine hundred eighty-nine thousand, eight hundred twenty-two".