193812138081 has 27 divisors (see below), whose sum is σ = 281537466483. Its totient is φ = 128479933440.

The previous prime is 193812138071. The next prime is 193812138151. The reversal of 193812138081 is 180831218391.

The square root of 193812138081 is 440241.

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

193812138081 is a `hidden beast` number, since 193 + 8 + 1 + 2 + 1 + 380 + 81 = 666.

It can be written as a sum of positive squares in only one way, i.e., 190807344225 + 3004793856 = 436815^2 + 54816^2 .

It is not a de Polignac number, because 193812138081 - 2⁹ = 193812137569 is a prime.

It is a super-2 number, since 2×193812138081² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (193812138001) 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, 339425526 + ... + 339426096.

Almost surely, 2^193812138081 is an apocalyptic number.

193812138081 is the 440241-st square number.

193812138081 is the 220121-st centered octagonal number.

It is an amenable number.

193812138081 is a deficient number, since it is larger than the sum of its proper divisors (87725328402).

193812138081 is an frugal number, since it uses more digits than its factorization.

193812138081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1662 (or 831 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 45.

The spelling of 193812138081 in words is "one hundred ninety-three billion, eight hundred twelve million, one hundred thirty-eight thousand, eighty-one".