20485405 has 4 divisors (see below), whose sum is σ = 24582492. Its totient is φ = 16388320.

The previous prime is 20485369. The next prime is 20485427. The reversal of 20485405 is 50458402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50458402 = 2 ⋅25229201.

It can be written as a sum of positive squares in 2 ways, for example, as 7257636 + 13227769 = 2694^2 + 3637^2 .

It is not a de Polignac number, because 20485405 - 2⁷ = 20485277 is a prime.

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 3 ways as a sum of consecutive naturals, for example, 2048536 + ... + 2048545.

It is an arithmetic number, because the mean of its divisors is an integer number (6145623).

Almost surely, 2^20485405 is an apocalyptic number.

It is an amenable number.

20485405 is a deficient number, since it is larger than the sum of its proper divisors (4097087).

20485405 is an equidigital number, since it uses as much as digits as its factorization.

20485405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4097086.

The product of its (nonzero) digits is 6400, while the sum is 28.

The square root of 20485405 is about 4526.0805339720. The cubic root of 20485405 is about 273.6202181533.

The spelling of 20485405 in words is "twenty million, four hundred eighty-five thousand, four hundred five".