181555527052081 has 64 divisors (see below), whose sum is σ = 231601629611520. Its totient is φ = 138429154805760.

The previous prime is 181555527052073. The next prime is 181555527052169. The reversal of 181555527052081 is 180250725555181.

It is a happy number.

181555527052081 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 181555527052081 - 2³ = 181555527052073 is a prime.

It is a super-2 number, since 2×181555527052081² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (181555527056081) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2962545066 + ... + 2962606348.

It is an arithmetic number, because the mean of its divisors is an integer number (3618775462680).

Almost surely, 2^{181555527052081} is an apocalyptic number.

It is an amenable number.

181555527052081 is a deficient number, since it is larger than the sum of its proper divisors (50046102559439).

181555527052081 is a wasteful number, since it uses less digits than its factorization.

181555527052081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63466.

The product of its (nonzero) digits is 5600000, while the sum is 55.

The spelling of 181555527052081 in words is "one hundred eighty-one trillion, five hundred fifty-five billion, five hundred twenty-seven million, fifty-two thousand, eighty-one".