20064643 has 4 divisors (see below), whose sum is σ = 20124520. Its totient is φ = 20004768.

The previous prime is 20064637. The next prime is 20064659. The reversal of 20064643 is 34646002.

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 20064643 - 2²¹ = 17967491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20067643) 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, 29433 + ... + 30106.

It is an arithmetic number, because the mean of its divisors is an integer number (5031130).

Almost surely, 2^20064643 is an apocalyptic number.

20064643 is a deficient number, since it is larger than the sum of its proper divisors (59877).

20064643 is an equidigital number, since it uses as much as digits as its factorization.

20064643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59876.

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

The square root of 20064643 is about 4479.3574315966. The cubic root of 20064643 is about 271.7338939767.

The spelling of 20064643 in words is "twenty million, sixty-four thousand, six hundred forty-three".