20643319 has 4 divisors (see below), whose sum is σ = 20652696. Its totient is φ = 20633944.

The previous prime is 20643313. The next prime is 20643323. The reversal of 20643319 is 91334602.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20643319 - 2⁷ = 20643191 is a prime.

It is a super-2 number, since 2×20643319² = 852293238671522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20643313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 612 + ... + 6454.

It is an arithmetic number, because the mean of its divisors is an integer number (5163174).

Almost surely, 2^20643319 is an apocalyptic number.

20643319 is a deficient number, since it is larger than the sum of its proper divisors (9377).

20643319 is an equidigital number, since it uses as much as digits as its factorization.

20643319 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9376.

The product of its (nonzero) digits is 3888, while the sum is 28.

The square root of 20643319 is about 4543.4919390266. The cubic root of 20643319 is about 274.3214964608.

The spelling of 20643319 in words is "twenty million, six hundred forty-three thousand, three hundred nineteen".