99768171321 has 135 divisors (see below), whose sum is σ = 183670448091. Its totient is φ = 52033677696.

The previous prime is 99768171319. The next prime is 99768171361. The reversal of 99768171321 is 12317186799.

It is a happy number.

The square root of 99768171321 is 315861.

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

99768171321 is a `hidden beast` number, since 9 + 97 + 68 + 171 + 321 = 666.

It can be written as a sum of positive squares in 7 ways, for example, as 89437481721 + 10330689600 = 299061^2 + 101640^2 .

It is not a de Polignac number, because 99768171321 - 2¹ = 99768171319 is a prime.

Its product of digits (1143072) is a multiple of the sum of its prime divisors (112).

It is not an unprimeable number, because it can be changed into a prime (99768171361) by changing a digit.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 1120990645 + ... + 1120990733.

Almost surely, 2^99768171321 is an apocalyptic number.

99768171321 is a gapful number since it is divisible by the number (91) formed by its first and last digit.

99768171321 is the 315861-st square number.

99768171321 is the 157931-st centered octagonal number.

It is an amenable number.

99768171321 is a deficient number, since it is larger than the sum of its proper divisors (83902276770).

99768171321 is an frugal number, since it uses more digits than its factorization.

99768171321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250 (or 112 counting only the distinct ones).

The product of its digits is 1143072, while the sum is 54.

The spelling of 99768171321 in words is "ninety-nine billion, seven hundred sixty-eight million, one hundred seventy-one thousand, three hundred twenty-one".