20345005 has 16 divisors (see below), whose sum is σ = 26552880. Its totient is φ = 14902272.

The previous prime is 20344997. The next prime is 20345009. The reversal of 20345005 is 50054302.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 13924 + 20331081 = 118^2 + 4509^2 .

It is a cyclic number.

It is not a de Polignac number, because 20345005 - 2³ = 20344997 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20345009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 90 + ... + 6379.

It is an arithmetic number, because the mean of its divisors is an integer number (1659555).

Almost surely, 2^20345005 is an apocalyptic number.

It is an amenable number.

20345005 is a deficient number, since it is larger than the sum of its proper divisors (6207875).

20345005 is a wasteful number, since it uses less digits than its factorization.

20345005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6528.

The product of its (nonzero) digits is 600, while the sum is 19.

The square root of 20345005 is about 4510.5437587945. The cubic root of 20345005 is about 272.9936846388.

Adding to 20345005 its reverse (50054302), we get a palindrome (70399307).

The spelling of 20345005 in words is "twenty million, three hundred forty-five thousand, five".