18636490 has 8 divisors (see below), whose sum is σ = 33545700. Its totient is φ = 7454592.

The previous prime is 18636481. The next prime is 18636517. The reversal of 18636490 is 9463681.

It is a Cunningham number, because it is equal to 4317²+1.

It can be written as a sum of positive squares in 2 ways, for example, as 18636489 + 1 = 4317^2 + 1^2 .

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

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, 931815 + ... + 931834.

Almost surely, 2^18636490 is an apocalyptic number.

18636490 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18636490 is a deficient number, since it is larger than the sum of its proper divisors (14909210).

18636490 is a wasteful number, since it uses less digits than its factorization.

18636490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1863656.

The product of its (nonzero) digits is 31104, while the sum is 37.

The square root of 18636490 is about 4317.0001158212. Note that the first 3 decimals coincide. The cubic root of 18636490 is about 265.1274573768.

The spelling of 18636490 in words is "eighteen million, six hundred thirty-six thousand, four hundred ninety".