20000221001987 has 2 divisors, whose sum is σ = 20000221001988. Its totient is φ = 20000221001986.

The previous prime is 20000221001977. The next prime is 20000221002007. The reversal of 20000221001987 is 78910012200002.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20000221001987 - 2¹² = 20000220997891 is a prime.

It is not a weakly prime, because it can be changed into another prime (20000221001947) 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 as a sum of consecutive naturals, namely, 10000110500993 + 10000110500994.

It is an arithmetic number, because the mean of its divisors is an integer number (10000110500994).

Almost surely, 2^{20000221001987} is an apocalyptic number.

20000221001987 is a deficient number, since it is larger than the sum of its proper divisors (1).

20000221001987 is an equidigital number, since it uses as much as digits as its factorization.

20000221001987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 32.

Adding to 20000221001987 its reverse (78910012200002), we get a palindrome (98910233201989).

The spelling of 20000221001987 in words is "twenty trillion, two hundred twenty-one million, one thousand, nine hundred eighty-seven".