161211364321 has 24 divisors (see below), whose sum is σ = 191102516352. Its totient is φ = 133213795200.

The previous prime is 161211364297. The next prime is 161211364339. The reversal of 161211364321 is 123463112161.

It is a de Polignac number, because none of the positive numbers 2^k-161211364321 is a prime.

It is a super-3 number, since 3×161211364321³ (a number of 35 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161211365321) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1723641 + ... + 1814761.

It is an arithmetic number, because the mean of its divisors is an integer number (7962604848).

Almost surely, 2^161211364321 is an apocalyptic number.

It is an amenable number.

161211364321 is a deficient number, since it is larger than the sum of its proper divisors (29891152031).

161211364321 is an equidigital number, since it uses as much as digits as its factorization.

161211364321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91453 (or 91422 counting only the distinct ones).

The product of its digits is 5184, while the sum is 31.

Adding to 161211364321 its reverse (123463112161), we get a palindrome (284674476482).

The spelling of 161211364321 in words is "one hundred sixty-one billion, two hundred eleven million, three hundred sixty-four thousand, three hundred twenty-one".