20085605 has 4 divisors (see below), whose sum is σ = 24102732. Its totient is φ = 16068480.

The previous prime is 20085589. The next prime is 20085623. The reversal of 20085605 is 50658002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50658002 = 2 ⋅25329001.

It can be written as a sum of positive squares in 2 ways, for example, as 13315201 + 6770404 = 3649^2 + 2602^2 .

It is not a de Polignac number, because 20085605 - 2⁴ = 20085589 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2008556 + ... + 2008565.

It is an arithmetic number, because the mean of its divisors is an integer number (6025683).

Almost surely, 2^20085605 is an apocalyptic number.

It is an amenable number.

20085605 is a deficient number, since it is larger than the sum of its proper divisors (4017127).

20085605 is an equidigital number, since it uses as much as digits as its factorization.

20085605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4017126.

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 20085605 is about 4481.6966653266. The cubic root of 20085605 is about 271.8284899520.

The spelling of 20085605 in words is "twenty million, eighty-five thousand, six hundred five".