20871919988 has 24 divisors (see below), whose sum is σ = 37498374144. Its totient is φ = 10160424800.

The previous prime is 20871919921. The next prime is 20871920021. The reversal of 20871919988 is 88991917802.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 20871919988.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 254723 + ... + 326538.

It is an arithmetic number, because the mean of its divisors is an integer number (1562432256).

Almost surely, 2^20871919988 is an apocalyptic number.

It is an amenable number.

20871919988 is a deficient number, since it is larger than the sum of its proper divisors (16626454156).

20871919988 is a wasteful number, since it uses less digits than its factorization.

20871919988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 581503 (or 581501 counting only the distinct ones).

The product of its (nonzero) digits is 5225472, while the sum is 62.

The spelling of 20871919988 in words is "twenty billion, eight hundred seventy-one million, nine hundred nineteen thousand, nine hundred eighty-eight".