20011001987 has 2 divisors, whose sum is σ = 20011001988. Its totient is φ = 20011001986.

The previous prime is 20011001833. The next prime is 20011002007. The reversal of 20011001987 is 78910011002.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20011001987 - 2¹⁸ = 20010739843 is a prime.

It is not a weakly prime, because it can be changed into another prime (20011000987) 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, 10005500993 + 10005500994.

It is an arithmetic number, because the mean of its divisors is an integer number (10005500994).

Almost surely, 2^20011001987 is an apocalyptic number.

20011001987 is a deficient number, since it is larger than the sum of its proper divisors (1).

20011001987 is an equidigital number, since it uses as much as digits as its factorization.

20011001987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 29.

Adding to 20011001987 its reverse (78910011002), we get a palindrome (98921012989).

The spelling of 20011001987 in words is "twenty billion, eleven million, one thousand, nine hundred eighty-seven".