172320736121 has 16 divisors (see below), whose sum is σ = 179131599360. Its totient is φ = 165568381440.

The previous prime is 172320736111. The next prime is 172320736129. The reversal of 172320736121 is 121637023271.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 172320736121 - 2¹⁴ = 172320719737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (172320736129) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33321866 + ... + 33327036.

It is an arithmetic number, because the mean of its divisors is an integer number (11195724960).

Almost surely, 2^172320736121 is an apocalyptic number.

It is an amenable number.

172320736121 is a deficient number, since it is larger than the sum of its proper divisors (6810863239).

172320736121 is a wasteful number, since it uses less digits than its factorization.

172320736121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10576.

The product of its (nonzero) digits is 21168, while the sum is 35.

Adding to 172320736121 its reverse (121637023271), we get a palindrome (293957759392).

The spelling of 172320736121 in words is "one hundred seventy-two billion, three hundred twenty million, seven hundred thirty-six thousand, one hundred twenty-one".