18861005 has 8 divisors (see below), whose sum is σ = 22666392. Its totient is φ = 15066688.

The previous prime is 18860999. The next prime is 18861019. The reversal of 18861005 is 50016881.

It can be written as a sum of positive squares in 4 ways, for example, as 362404 + 18498601 = 602^2 + 4301^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 18861005 - 2¹² = 18856909 is a prime.

It is a super-2 number, since 2×18861005² = 711475019220050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1619 + ... + 6351.

It is an arithmetic number, because the mean of its divisors is an integer number (2833299).

Almost surely, 2^18861005 is an apocalyptic number.

It is an amenable number.

18861005 is a deficient number, since it is larger than the sum of its proper divisors (3805387).

18861005 is an equidigital number, since it uses as much as digits as its factorization.

18861005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5535.

The product of its (nonzero) digits is 1920, while the sum is 29.

The square root of 18861005 is about 4342.9258570692. The cubic root of 18861005 is about 266.1878795908.

Adding to 18861005 its reverse (50016881), we get a palindrome (68877886).

The spelling of 18861005 in words is "eighteen million, eight hundred sixty-one thousand, five".