20871647999 has 8 divisors (see below), whose sum is σ = 21469082880. Its totient is φ = 20280603096.

The previous prime is 20871647959. The next prime is 20871648019. The reversal of 20871647999 is 99974617802.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20871647999 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20871647959) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1590869 + ... + 1603934.

It is an arithmetic number, because the mean of its divisors is an integer number (2683635360).

Almost surely, 2^20871647999 is an apocalyptic number.

20871647999 is a deficient number, since it is larger than the sum of its proper divisors (597434881).

20871647999 is a wasteful number, since it uses less digits than its factorization.

20871647999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3194989.

The product of its (nonzero) digits is 13716864, while the sum is 62.

The spelling of 20871647999 in words is "twenty billion, eight hundred seventy-one million, six hundred forty-seven thousand, nine hundred ninety-nine".