18747081 has 6 divisors (see below), whose sum is σ = 27079130. Its totient is φ = 12498048.

The previous prime is 18747059. The next prime is 18747089. The reversal of 18747081 is 18074781.

18747081 is a `hidden beast` number, since 187 + 470 + 8 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 18662400 + 84681 = 4320^2 + 291^2 .

It is not a de Polignac number, because 18747081 - 2⁷ = 18746953 is a prime.

It is a super-2 number, since 2×18747081² = 702906092041122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18747089) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1041496 + ... + 1041513.

Almost surely, 2^18747081 is an apocalyptic number.

It is an amenable number.

18747081 is a deficient number, since it is larger than the sum of its proper divisors (8332049).

18747081 is a wasteful number, since it uses less digits than its factorization.

18747081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2083015 (or 2083012 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 36.

The square root of 18747081 is about 4329.7899487158. The cubic root of 18747081 is about 265.6508553563.

The spelling of 18747081 in words is "eighteen million, seven hundred forty-seven thousand, eighty-one".