161213321 has 8 divisors (see below), whose sum is σ = 166667424. Its totient is φ = 155836800.

The previous prime is 161213317. The next prime is 161213389. The reversal of 161213321 is 123312161.

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

It is a cyclic number.

It is not a de Polignac number, because 161213321 - 2² = 161213317 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161213293 and 161213302.

It is not an unprimeable number, because it can be changed into a prime (161203321) 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, 15155 + ... + 23496.

It is an arithmetic number, because the mean of its divisors is an integer number (20833428).

Almost surely, 2^161213321 is an apocalyptic number.

It is an amenable number.

161213321 is a deficient number, since it is larger than the sum of its proper divisors (5454103).

161213321 is an equidigital number, since it uses as much as digits as its factorization.

161213321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38791.

The product of its digits is 216, while the sum is 20.

The square root of 161213321 is about 12696.9807828476. The cubic root of 161213321 is about 544.2523440454.

Adding to 161213321 its reverse (123312161), we get a palindrome (284525482).

The spelling of 161213321 in words is "one hundred sixty-one million, two hundred thirteen thousand, three hundred twenty-one".