18181081 has 8 divisors (see below), whose sum is σ = 19605600. Its totient is φ = 16803360.

The previous prime is 18181039. The next prime is 18181103. The reversal of 18181081 is 18018181.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18181081 - 2²¹ = 16083929 is a prime.

It is a super-2 number, since 2×18181081² = 661103412657122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18181021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10891 + ... + 12448.

It is an arithmetic number, because the mean of its divisors is an integer number (2450700).

Almost surely, 2^18181081 is an apocalyptic number.

It is an amenable number.

18181081 is a deficient number, since it is larger than the sum of its proper divisors (1424519).

18181081 is a wasteful number, since it uses less digits than its factorization.

18181081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23399.

The product of its (nonzero) digits is 512, while the sum is 28.

The square root of 18181081 is about 4263.9278840055. The cubic root of 18181081 is about 262.9500355671.

The spelling of 18181081 in words is "eighteen million, one hundred eighty-one thousand, eighty-one".