20105671547 has 4 divisors (see below), whose sum is σ = 21652261680. Its totient is φ = 18559081416.

The previous prime is 20105671517. The next prime is 20105671591. The reversal of 20105671547 is 74517650102.

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 20105671547 - 2²⁰ = 20104622971 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 20105671547.

It is not an unprimeable number, because it can be changed into a prime (20105671517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 773295047 + ... + 773295072.

It is an arithmetic number, because the mean of its divisors is an integer number (5413065420).

Almost surely, 2^20105671547 is an apocalyptic number.

20105671547 is a deficient number, since it is larger than the sum of its proper divisors (1546590133).

20105671547 is a wasteful number, since it uses less digits than its factorization.

20105671547 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1546590132.

The product of its (nonzero) digits is 58800, while the sum is 38.

The spelling of 20105671547 in words is "twenty billion, one hundred five million, six hundred seventy-one thousand, five hundred forty-seven".