18861685 has 4 divisors (see below), whose sum is σ = 22634028. Its totient is φ = 15089344.

The previous prime is 18861683. The next prime is 18861707. The reversal of 18861685 is 58616881.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6765201 + 12096484 = 2601^2 + 3478^2 .

It is a cyclic number.

It is not a de Polignac number, because 18861685 - 2¹ = 18861683 is a prime.

It is a super-2 number, since 2×18861685² = 711526322078450, 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 (18861683) 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, 1886164 + ... + 1886173.

It is an arithmetic number, because the mean of its divisors is an integer number (5658507).

Almost surely, 2^18861685 is an apocalyptic number.

It is an amenable number.

18861685 is a deficient number, since it is larger than the sum of its proper divisors (3772343).

18861685 is an equidigital number, since it uses as much as digits as its factorization.

18861685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3772342.

The product of its digits is 92160, while the sum is 43.

The square root of 18861685 is about 4343.0041445985. The cubic root of 18861685 is about 266.1910785292.

The spelling of 18861685 in words is "eighteen million, eight hundred sixty-one thousand, six hundred eighty-five".