20018605 has 8 divisors (see below), whose sum is σ = 25435512. Its totient is φ = 15072768.

The previous prime is 20018587. The next prime is 20018617. The reversal of 20018605 is 50681002.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 6135529 + 13883076 = 2477^2 + 3726^2 .

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 20018605 - 2⁷ = 20018477 is a prime.

It is a super-2 number, since 2×20018605² = 801489092292050, 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, 117672 + ... + 117841.

It is an arithmetic number, because the mean of its divisors is an integer number (3179439).

Almost surely, 2^20018605 is an apocalyptic number.

It is an amenable number.

20018605 is a deficient number, since it is larger than the sum of its proper divisors (5416907).

20018605 is a wasteful number, since it uses less digits than its factorization.

20018605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235535.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 20018605 is about 4474.2155737067. The cubic root of 20018605 is about 271.5259051397.

Adding to 20018605 its reverse (50681002), we get a palindrome (70699607).

The spelling of 20018605 in words is "twenty million, eighteen thousand, six hundred five".