18980181 has 36 divisors (see below), whose sum is σ = 31225740. Its totient is φ = 11088000.

The previous prime is 18980167. The next prime is 18980231. The reversal of 18980181 is 18108981.

It can be written as a sum of positive squares in 2 ways, for example, as 13176900 + 5803281 = 3630^2 + 2409^2 .

It is not a de Polignac number, because 18980181 - 2⁷ = 18980053 is a prime.

It is a super-2 number, since 2×18980181² = 720494541585522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18980141) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 31281 + ... + 31881.

Almost surely, 2^18980181 is an apocalyptic number.

18980181 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18980181 is a deficient number, since it is larger than the sum of its proper divisors (12245559).

18980181 is a wasteful number, since it uses less digits than its factorization.

18980181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 658 (or 644 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 36.

The square root of 18980181 is about 4356.6249551689. The cubic root of 18980181 is about 266.7473518000.

The spelling of 18980181 in words is "eighteen million, nine hundred eighty thousand, one hundred eighty-one".