20447645443 has 4 divisors (see below), whose sum is σ = 20833450128. Its totient is φ = 20061840760.

The previous prime is 20447645429. The next prime is 20447645447. The reversal of 20447645443 is 34454674402.

It is a happy number.

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 20447645443 - 2⁵ = 20447645411 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20447645443.

It is not an unprimeable number, because it can be changed into a prime (20447645447) 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, 192902263 + ... + 192902368.

It is an arithmetic number, because the mean of its divisors is an integer number (5208362532).

Almost surely, 2^20447645443 is an apocalyptic number.

20447645443 is a deficient number, since it is larger than the sum of its proper divisors (385804685).

20447645443 is an equidigital number, since it uses as much as digits as its factorization.

20447645443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 385804684.

The product of its (nonzero) digits is 1290240, while the sum is 43.

The spelling of 20447645443 in words is "twenty billion, four hundred forty-seven million, six hundred forty-five thousand, four hundred forty-three".