168740385780121 has 15 divisors (see below), whose sum is σ = 171601880844665. Its totient is φ = 165926606507400.

The previous prime is 168740385780119. The next prime is 168740385780179. The reversal of 168740385780121 is 121087583047861.

It is a happy number.

The square root of 168740385780121 is 12990011.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 2 ways, for example, as 147505615845721 + 21234769934400 = 12145189^2 + 4608120^2 .

It is not a de Polignac number, because 168740385780121 - 2¹ = 168740385780119 is a prime.

It is a super-2 number, since 2×168740385780121² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (61).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 168740385780121.

It is not an unprimeable number, because it can be changed into a prime (168740385783121) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 48335829186 + ... + 48335832676.

Almost surely, 2^{168740385780121} is an apocalyptic number.

168740385780121 is the 12990011-st square number.

168740385780121 is the 6495006-th centered octagonal number.

It is an amenable number.

168740385780121 is a deficient number, since it is larger than the sum of its proper divisors (2861495064544).

168740385780121 is an frugal number, since it uses more digits than its factorization.

168740385780121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7226 (or 3552 counting only the distinct ones).

The product of its (nonzero) digits is 18063360, while the sum is 61.

The spelling of 168740385780121 in words is "one hundred sixty-eight trillion, seven hundred forty billion, three hundred eighty-five million, seven hundred eighty thousand, one hundred twenty-one".