201189028681 has 9 divisors (see below), whose sum is σ = 203246487669. Its totient is φ = 199152204000.

The previous prime is 201189028673. The next prime is 201189028717. The reversal of 201189028681 is 186820981102.

It is a happy number.

The square root of 201189028681 is 448541.

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

It can be written as a sum of positive squares in 4 ways, for example, as 41428938681 + 159760090000 = 203541^2 + 399700^2 .

It is not a de Polignac number, because 201189028681 - 2³ = 201189028673 is a prime.

It is a super-2 number, since 2×201189028681² (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 (201189026681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 45300421 + ... + 45304861.

Almost surely, 2^201189028681 is an apocalyptic number.

201189028681 is the 448541-st square number.

201189028681 is the 224271-st centered octagonal number.

It is an amenable number.

201189028681 is a deficient number, since it is larger than the sum of its proper divisors (2057458988).

201189028681 is an frugal number, since it uses more digits than its factorization.

201189028681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9084 (or 4542 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 46.

The spelling of 201189028681 in words is "two hundred one billion, one hundred eighty-nine million, twenty-eight thousand, six hundred eighty-one".