18743481 has 30 divisors (see below), whose sum is σ = 29596842. Its totient is φ = 11819520.

The previous prime is 18743477. The next prime is 18743509. The reversal of 18743481 is 18434781.

It can be written as a sum of positive squares in only one way, i.e., 18275625 + 467856 = 4275^2 + 684^2 .

It is not a de Polignac number, because 18743481 - 2² = 18743477 is a prime.

It is a super-2 number, since 2×18743481² = 702636159994722, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18743471) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 28921 + ... + 29561.

Almost surely, 2^18743481 is an apocalyptic number.

It is an amenable number.

18743481 is a deficient number, since it is larger than the sum of its proper divisors (10853361).

18743481 is an equidigital number, since it uses as much as digits as its factorization.

18743481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 691 (or 663 counting only the distinct ones).

The product of its digits is 21504, while the sum is 36.

The square root of 18743481 is about 4329.3742042009. The cubic root of 18743481 is about 265.6338499658.

The spelling of 18743481 in words is "eighteen million, seven hundred forty-three thousand, four hundred eighty-one".