20771821867 has 8 divisors (see below), whose sum is σ = 21346083216. Its totient is φ = 20198237472.

The previous prime is 20771821853. The next prime is 20771821883. The reversal of 20771821867 is 76812817702.

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-20771821867 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20771821867.

It is not an unprimeable number, because it can be changed into a prime (20771821067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 106708 + ... + 230065.

It is an arithmetic number, because the mean of its divisors is an integer number (2668260402).

Almost surely, 2^20771821867 is an apocalyptic number.

20771821867 is a deficient number, since it is larger than the sum of its proper divisors (574261349).

20771821867 is a wasteful number, since it uses less digits than its factorization.

20771821867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 338477.

The product of its (nonzero) digits is 526848, while the sum is 49.

The spelling of 20771821867 in words is "twenty billion, seven hundred seventy-one million, eight hundred twenty-one thousand, eight hundred sixty-seven".