20402245 has 4 divisors (see below), whose sum is σ = 24482700. Its totient is φ = 16321792.

The previous prime is 20402233. The next prime is 20402251. The reversal of 20402245 is 54220402.

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 16265089 + 4137156 = 4033^2 + 2034^2 .

It is a cyclic number.

It is not a de Polignac number, because 20402245 - 2¹¹ = 20400197 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2040220 + ... + 2040229.

It is an arithmetic number, because the mean of its divisors is an integer number (6120675).

Almost surely, 2^20402245 is an apocalyptic number.

It is an amenable number.

20402245 is a deficient number, since it is larger than the sum of its proper divisors (4080455).

20402245 is an equidigital number, since it uses as much as digits as its factorization.

20402245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4080454.

The product of its (nonzero) digits is 640, while the sum is 19.

The square root of 20402245 is about 4516.8844350946. The cubic root of 20402245 is about 273.2494644860.

Adding to 20402245 its reverse (54220402), we get a palindrome (74622647).

The spelling of 20402245 in words is "twenty million, four hundred two thousand, two hundred forty-five".