20312645 has 8 divisors (see below), whose sum is σ = 24403704. Its totient is φ = 16231104.

The previous prime is 20312639. The next prime is 20312681. The reversal of 20312645 is 54621302.

It can be written as a sum of positive squares in 4 ways, for example, as 1503076 + 18809569 = 1226^2 + 4337^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20312645 - 2⁴ = 20312629 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20312645.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 3767 + ... + 7403.

It is an arithmetic number, because the mean of its divisors is an integer number (3050463).

Almost surely, 2^20312645 is an apocalyptic number.

It is an amenable number.

20312645 is a deficient number, since it is larger than the sum of its proper divisors (4091059).

20312645 is a wasteful number, since it uses less digits than its factorization.

20312645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4759.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 20312645 is about 4506.9551806070. The cubic root of 20312645 is about 272.8488700026.

Adding to 20312645 its reverse (54621302), we get a palindrome (74933947).

The spelling of 20312645 in words is "twenty million, three hundred twelve thousand, six hundred forty-five".