20643369 has 4 divisors (see below), whose sum is σ = 27524496. Its totient is φ = 13762244.

The previous prime is 20643353. The next prime is 20643379. The reversal of 20643369 is 96334602.

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.

It is a cyclic number.

It is not a de Polignac number, because 20643369 - 2⁴ = 20643353 is a prime.

It is a super-2 number, since 2×20643369² = 852297367340322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20643379) 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, 3440559 + ... + 3440564.

It is an arithmetic number, because the mean of its divisors is an integer number (6881124).

Almost surely, 2^20643369 is an apocalyptic number.

It is an amenable number.

20643369 is a deficient number, since it is larger than the sum of its proper divisors (6881127).

20643369 is an equidigital number, since it uses as much as digits as its factorization.

20643369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6881126.

The product of its (nonzero) digits is 23328, while the sum is 33.

The square root of 20643369 is about 4543.4974413991. The cubic root of 20643369 is about 274.3217179378.

It can be divided in two parts, 20643 and 369, that added together give a palindrome (21012).

The spelling of 20643369 in words is "twenty million, six hundred forty-three thousand, three hundred sixty-nine".