18604381 has 4 divisors (see below), whose sum is σ = 18647200. Its totient is φ = 18561564.

The previous prime is 18604373. The next prime is 18604387. The reversal of 18604381 is 18340681.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18604381 - 2³ = 18604373 is a prime.

It is a super-2 number, since 2×18604381² = 692245984786322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18604387) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20751 + ... + 21628.

It is an arithmetic number, because the mean of its divisors is an integer number (4661800).

Almost surely, 2^18604381 is an apocalyptic number.

It is an amenable number.

18604381 is a deficient number, since it is larger than the sum of its proper divisors (42819).

18604381 is an equidigital number, since it uses as much as digits as its factorization.

18604381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42818.

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 18604381 is about 4313.2796106907. The cubic root of 18604381 is about 264.9751062412.

It can be divided in two parts, 1860 and 4381, that added together give a square (6241 = 79²).

The spelling of 18604381 in words is "eighteen million, six hundred four thousand, three hundred eighty-one".