20644313 has 4 divisors (see below), whose sum is σ = 20655888. Its totient is φ = 20632740.

The previous prime is 20644303. The next prime is 20644319. The reversal of 20644313 is 31344602.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 31344602 = 2 ⋅15672301.

It is a cyclic number.

It is not a de Polignac number, because 20644313 - 2¹⁸ = 20382169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20644319) 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, 2483 + ... + 6888.

It is an arithmetic number, because the mean of its divisors is an integer number (5163972).

Almost surely, 2^20644313 is an apocalyptic number.

It is an amenable number.

20644313 is a deficient number, since it is larger than the sum of its proper divisors (11575).

20644313 is an equidigital number, since it uses as much as digits as its factorization.

20644313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11574.

The product of its (nonzero) digits is 1728, while the sum is 23.

The square root of 20644313 is about 4543.6013249404. The cubic root of 20644313 is about 274.3258993573.

Adding to 20644313 its reverse (31344602), we get a palindrome (51988915).

The spelling of 20644313 in words is "twenty million, six hundred forty-four thousand, three hundred thirteen".