161221142 has 8 divisors (see below), whose sum is σ = 249632832. Its totient is φ = 78010200.

The previous prime is 161221127. The next prime is 161221171. The reversal of 161221142 is 241122161.

It is a happy number.

161221142 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1300109 + ... + 1300232.

It is an arithmetic number, because the mean of its divisors is an integer number (31204104).

Almost surely, 2^161221142 is an apocalyptic number.

161221142 is a deficient number, since it is larger than the sum of its proper divisors (88411690).

161221142 is a wasteful number, since it uses less digits than its factorization.

161221142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2600374.

The product of its digits is 192, while the sum is 20.

The square root of 161221142 is about 12697.2887657169. The cubic root of 161221142 is about 544.2611450731.

The spelling of 161221142 in words is "one hundred sixty-one million, two hundred twenty-one thousand, one hundred forty-two".