161161221 has 8 divisors (see below), whose sum is σ = 231411040. Its totient is φ = 99176112.

The previous prime is 161161213. The next prime is 161161223. The reversal of 161161221 is 122161161.

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

It is not a de Polignac number, because 161161221 - 2³ = 161161213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161161223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2066131 + ... + 2066208.

It is an arithmetic number, because the mean of its divisors is an integer number (28926380).

Almost surely, 2^161161221 is an apocalyptic number.

It is an amenable number.

161161221 is a deficient number, since it is larger than the sum of its proper divisors (70249819).

161161221 is a wasteful number, since it uses less digits than its factorization.

161161221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4132355.

The product of its digits is 144, while the sum is 21.

The square root of 161161221 is about 12694.9289482061. The cubic root of 161161221 is about 544.1937082740.

The spelling of 161161221 in words is "one hundred sixty-one million, one hundred sixty-one thousand, two hundred twenty-one".