20643343 has 4 divisors (see below), whose sum is σ = 23592400. Its totient is φ = 17694288.

The previous prime is 20643323. The next prime is 20643347. The reversal of 20643343 is 34334602.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20643343 is a prime.

It is a super-3 number, since 3×20643343³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20643347) 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, 1474518 + ... + 1474531.

It is an arithmetic number, because the mean of its divisors is an integer number (5898100).

Almost surely, 2^20643343 is an apocalyptic number.

20643343 is a deficient number, since it is larger than the sum of its proper divisors (2949057).

20643343 is an equidigital number, since it uses as much as digits as its factorization.

20643343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2949056.

The product of its (nonzero) digits is 5184, while the sum is 25.

The square root of 20643343 is about 4543.4945801662. The cubic root of 20643343 is about 274.3216027698.

Adding to 20643343 its reverse (34334602), we get a palindrome (54977945).

The spelling of 20643343 in words is "twenty million, six hundred forty-three thousand, three hundred forty-three".