201155168581 has 4 divisors (see below), whose sum is σ = 201384536812. Its totient is φ = 200925800352.

The previous prime is 201155168579. The next prime is 201155168587. The reversal of 201155168581 is 185861551102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 165005751681 + 36149416900 = 406209^2 + 190130^2 .

It is a cyclic number.

It is not a de Polignac number, because 201155168581 - 2¹ = 201155168579 is a prime.

It is a super-2 number, since 2×201155168581² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201155168587) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 114682800 + ... + 114684553.

It is an arithmetic number, because the mean of its divisors is an integer number (50346134203).

Almost surely, 2^201155168581 is an apocalyptic number.

It is an amenable number.

201155168581 is a deficient number, since it is larger than the sum of its proper divisors (229368231).

201155168581 is an equidigital number, since it uses as much as digits as its factorization.

201155168581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 229368230.

The product of its (nonzero) digits is 96000, while the sum is 43.

The spelling of 201155168581 in words is "two hundred one billion, one hundred fifty-five million, one hundred sixty-eight thousand, five hundred eighty-one".