20157205 has 4 divisors (see below), whose sum is σ = 24188652. Its totient is φ = 16125760.

The previous prime is 20157187. The next prime is 20157209. The reversal of 20157205 is 50275102.

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 6922161 + 13235044 = 2631^2 + 3638^2 .

It is not a de Polignac number, because 20157205 - 2⁷ = 20157077 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20157209) 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, 2015716 + ... + 2015725.

It is an arithmetic number, because the mean of its divisors is an integer number (6047163).

Almost surely, 2^20157205 is an apocalyptic number.

It is an amenable number.

20157205 is a deficient number, since it is larger than the sum of its proper divisors (4031447).

20157205 is an equidigital number, since it uses as much as digits as its factorization.

20157205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4031446.

The product of its (nonzero) digits is 700, while the sum is 22.

The square root of 20157205 is about 4489.6776053521. The cubic root of 20157205 is about 272.1511063865.

The spelling of 20157205 in words is "twenty million, one hundred fifty-seven thousand, two hundred five".