18357811081 has 9 divisors (see below), whose sum is σ = 18496917831. Its totient is φ = 18219745752.

The previous prime is 18357811079. The next prime is 18357811099. The reversal of 18357811081 is 18011875381.

The square root of 18357811081 is 135491.

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

It can be written as a sum of positive squares in only one way, i.e., 5380956025 + 12976855056 = 73355^2 + 113916^2 .

It is not a de Polignac number, because 18357811081 - 2¹ = 18357811079 is a prime.

It is a super-3 number, since 3×18357811081³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18357811051) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 21271656 + ... + 21272518.

Almost surely, 2^18357811081 is an apocalyptic number.

18357811081 is the 135491-st square number.

18357811081 is the 67746-th centered octagonal number.

It is an amenable number.

18357811081 is a deficient number, since it is larger than the sum of its proper divisors (139106750).

18357811081 is an frugal number, since it uses more digits than its factorization.

18357811081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2040 (or 1020 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 43.

The spelling of 18357811081 in words is "eighteen billion, three hundred fifty-seven million, eight hundred eleven thousand, eighty-one".