161213643 has 12 divisors (see below), whose sum is σ = 235126320. Its totient is φ = 106431696.

The previous prime is 161213627. The next prime is 161213707. The reversal of 161213643 is 346312161.

161213643 is a `hidden beast` number, since 1 + 6 + 1 + 2 + 13 + 643 = 666.

It is not a de Polignac number, because 161213643 - 2⁴ = 161213627 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161213743) 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 11 ways as a sum of consecutive naturals, for example, 86028 + ... + 87881.

It is an arithmetic number, because the mean of its divisors is an integer number (19593860).

Almost surely, 2^161213643 is an apocalyptic number.

161213643 is a deficient number, since it is larger than the sum of its proper divisors (73912677).

161213643 is a wasteful number, since it uses less digits than its factorization.

161213643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174018 (or 174015 counting only the distinct ones).

The product of its digits is 2592, while the sum is 27.

The square root of 161213643 is about 12696.9934630211. The cubic root of 161213643 is about 544.2527063999.

The spelling of 161213643 in words is "one hundred sixty-one million, two hundred thirteen thousand, six hundred forty-three".