161391222 has 12 divisors (see below), whose sum is σ = 349681020. Its totient is φ = 53797068.

The previous prime is 161391199. The next prime is 161391227. The reversal of 161391222 is 222193161.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161391227) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4483072 + ... + 4483107.

It is an arithmetic number, because the mean of its divisors is an integer number (29140085).

Almost surely, 2^161391222 is an apocalyptic number.

161391222 is an abundant number, since it is smaller than the sum of its proper divisors (188289798).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161391222 is a wasteful number, since it uses less digits than its factorization.

161391222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8966187 (or 8966184 counting only the distinct ones).

The product of its digits is 1296, while the sum is 27.

The square root of 161391222 is about 12703.9844930636. The cubic root of 161391222 is about 544.4524669680.

The spelling of 161391222 in words is "one hundred sixty-one million, three hundred ninety-one thousand, two hundred twenty-two".