18581481 has 28 divisors (see below), whose sum is σ = 28330560. Its totient is φ = 12179160.

The previous prime is 18581477. The next prime is 18581483. The reversal of 18581481 is 18418581.

It is a happy number.

It is not a de Polignac number, because 18581481 - 2² = 18581477 is a prime.

It is a super-2 number, since 2×18581481² = 690542872306722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18581483) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 51580 + ... + 51938.

Almost surely, 2^18581481 is an apocalyptic number.

It is an amenable number.

18581481 is a deficient number, since it is larger than the sum of its proper divisors (9749079).

18581481 is an frugal number, since it uses more digits than its factorization.

18581481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 448 (or 433 counting only the distinct ones).

The product of its digits is 10240, while the sum is 36.

The square root of 18581481 is about 4310.6242007394. The cubic root of 18581481 is about 264.8663429469.

The spelling of 18581481 in words is "eighteen million, five hundred eighty-one thousand, four hundred eighty-one".