18561938 has 8 divisors (see below), whose sum is σ = 28595532. Its totient is φ = 9030096.

The previous prime is 18561923. The next prime is 18561941. The reversal of 18561938 is 83916581.

It can be written as a sum of positive squares in 2 ways, for example, as 16056049 + 2505889 = 4007^2 + 1583^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 18561895 and 18561904.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 125345 + ... + 125492.

Almost surely, 2^18561938 is an apocalyptic number.

18561938 is a deficient number, since it is larger than the sum of its proper divisors (10033594).

18561938 is a wasteful number, since it uses less digits than its factorization.

18561938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250876.

The product of its digits is 51840, while the sum is 41.

The square root of 18561938 is about 4308.3567633148. The cubic root of 18561938 is about 264.7734529935.

The spelling of 18561938 in words is "eighteen million, five hundred sixty-one thousand, nine hundred thirty-eight".