172131621312218 has 32 divisors (see below), whose sum is σ = 277011381936960. Its totient is φ = 79935694209280.

The previous prime is 172131621312193. The next prime is 172131621312229. The reversal of 172131621312218 is 812213126131271.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 107153921 + ... + 108748452.

It is an arithmetic number, because the mean of its divisors is an integer number (8656605685530).

Almost surely, 2^{172131621312218} is an apocalyptic number.

172131621312218 is a deficient number, since it is larger than the sum of its proper divisors (104879760624742).

172131621312218 is a wasteful number, since it uses less digits than its factorization.

172131621312218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215902702.

The product of its digits is 48384, while the sum is 41.

Adding to 172131621312218 its reverse (812213126131271), we get a palindrome (984344747443489).

The spelling of 172131621312218 in words is "one hundred seventy-two trillion, one hundred thirty-one billion, six hundred twenty-one million, three hundred twelve thousand, two hundred eighteen".