20543671667 has 4 divisors (see below), whose sum is σ = 20553798720. Its totient is φ = 20533544616.

The previous prime is 20543671649. The next prime is 20543671721. The reversal of 20543671667 is 76617634502.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20543671667 is a prime.

It is a super-2 number, since 2×20543671667² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20543671627) 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, 5060483 + ... + 5064540.

It is an arithmetic number, because the mean of its divisors is an integer number (5138449680).

Almost surely, 2^20543671667 is an apocalyptic number.

20543671667 is a deficient number, since it is larger than the sum of its proper divisors (10127053).

20543671667 is a wasteful number, since it uses less digits than its factorization.

20543671667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10127052.

The product of its (nonzero) digits is 1270080, while the sum is 47.

The spelling of 20543671667 in words is "twenty billion, five hundred forty-three million, six hundred seventy-one thousand, six hundred sixty-seven".