20512319987 has 2 divisors, whose sum is σ = 20512319988. Its totient is φ = 20512319986.

The previous prime is 20512319983. The next prime is 20512320007. The reversal of 20512319987 is 78991321502.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20512319987 - 2² = 20512319983 is a prime.

It is not a weakly prime, because it can be changed into another prime (20512319983) 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, 10256159993 + 10256159994.

It is an arithmetic number, because the mean of its divisors is an integer number (10256159994).

Almost surely, 2^20512319987 is an apocalyptic number.

20512319987 is a deficient number, since it is larger than the sum of its proper divisors (1).

20512319987 is an equidigital number, since it uses as much as digits as its factorization.

20512319987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 272160, while the sum is 47.

The spelling of 20512319987 in words is "twenty billion, five hundred twelve million, three hundred nineteen thousand, nine hundred eighty-seven".