193678327921 has 27 divisors (see below), whose sum is σ = 212515988931. Its totient is φ = 176429919744.

The previous prime is 193678327901. The next prime is 193678327943. The reversal of 193678327921 is 129723876391.

The square root of 193678327921 is 440089.

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

It can be written as a sum of positive squares in 13 ways, for example, as 134220382321 + 59457945600 = 366361^2 + 243840^2 .

It is not a de Polignac number, because 193678327921 - 2²³ = 193669939313 is a prime.

It is a super-2 number, since 2×193678327921² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (193678327901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 554952055 + ... + 554952403.

It is an arithmetic number, because the mean of its divisors is an integer number (7870962553).

Almost surely, 2^193678327921 is an apocalyptic number.

193678327921 is the 440089-th square number.

193678327921 is the 220045-th centered octagonal number.

It is an amenable number.

193678327921 is a deficient number, since it is larger than the sum of its proper divisors (18837661010).

193678327921 is an frugal number, since it uses more digits than its factorization.

193678327921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 918 (or 459 counting only the distinct ones).

The product of its digits is 6858432, while the sum is 58.

The spelling of 193678327921 in words is "one hundred ninety-three billion, six hundred seventy-eight million, three hundred twenty-seven thousand, nine hundred twenty-one".