20645313 has 16 divisors (see below), whose sum is σ = 30090816. Its totient is φ = 12513600.

The previous prime is 20645311. The next prime is 20645321. The reversal of 20645313 is 31354602.

It is a happy number.

It is not a de Polignac number, because 20645313 - 2¹ = 20645311 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20645311) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 1338 + ... + 6563.

It is an arithmetic number, because the mean of its divisors is an integer number (1880676).

Almost surely, 2^20645313 is an apocalyptic number.

It is an amenable number.

20645313 is a deficient number, since it is larger than the sum of its proper divisors (9445503).

20645313 is a wasteful number, since it uses less digits than its factorization.

20645313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7984.

The product of its (nonzero) digits is 2160, while the sum is 24.

The square root of 20645313 is about 4543.7113684740. The cubic root of 20645313 is about 274.3303286880.

Adding to 20645313 its reverse (31354602), we get a palindrome (51999915).

The spelling of 20645313 in words is "twenty million, six hundred forty-five thousand, three hundred thirteen".