20021211021987 has 96 divisors (see below), whose sum is σ = 35178219648000. Its totient is φ = 10711375386624.

The previous prime is 20021211021979. The next prime is 20021211021989. The reversal of 20021211021987 is 78912011212002.

20021211021987 is a `hidden beast` number, since 200 + 21 + 211 + 0 + 219 + 8 + 7 = 666.

It is not a de Polignac number, because 20021211021987 - 2³ = 20021211021979 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20021211021989) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1838658439 + ... + 1838669327.

It is an arithmetic number, because the mean of its divisors is an integer number (366439788000).

Almost surely, 2^{20021211021987} is an apocalyptic number.

20021211021987 is a deficient number, since it is larger than the sum of its proper divisors (15157008626013).

20021211021987 is a wasteful number, since it uses less digits than its factorization.

20021211021987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19745 (or 19742 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 36.

Adding to 20021211021987 its reverse (78912011212002), we get a palindrome (98933222233989).

The spelling of 20021211021987 in words is "twenty trillion, twenty-one billion, two hundred eleven million, twenty-one thousand, nine hundred eighty-seven".