168121788321 has 16 divisors (see below), whose sum is σ = 225652255488. Its totient is φ = 111338035200.

The previous prime is 168121788277. The next prime is 168121788353. The reversal of 168121788321 is 123887121861.

It is not a de Polignac number, because 168121788321 - 2¹³ = 168121780129 is a prime.

It is a super-2 number, since 2×168121788321² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (168121788721) 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, 156936 + ... + 600726.

It is an arithmetic number, because the mean of its divisors is an integer number (14103265968).

Almost surely, 2^168121788321 is an apocalyptic number.

It is an amenable number.

168121788321 is a deficient number, since it is larger than the sum of its proper divisors (57530467167).

168121788321 is a wasteful number, since it uses less digits than its factorization.

168121788321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 444632.

The product of its digits is 258048, while the sum is 48.

The spelling of 168121788321 in words is "one hundred sixty-eight billion, one hundred twenty-one million, seven hundred eighty-eight thousand, three hundred twenty-one".