20604643 has 4 divisors (see below), whose sum is σ = 20817160. Its totient is φ = 20392128.

The previous prime is 20604613. The next prime is 20604679. The reversal of 20604643 is 34640602.

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

It is a cyclic number.

It is not a de Polignac number, because 20604643 - 2⁹ = 20604131 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20604613) 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, 106113 + ... + 106306.

It is an arithmetic number, because the mean of its divisors is an integer number (5204290).

Almost surely, 2^20604643 is an apocalyptic number.

20604643 is a deficient number, since it is larger than the sum of its proper divisors (212517).

20604643 is an equidigital number, since it uses as much as digits as its factorization.

20604643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212516.

The product of its (nonzero) digits is 3456, while the sum is 25.

The square root of 20604643 is about 4539.2337459091. The cubic root of 20604643 is about 274.1500722991.

The spelling of 20604643 in words is "twenty million, six hundred four thousand, six hundred forty-three".