999999987787 has 2 divisors, whose sum is σ = 999999987788. Its totient is φ = 999999987786.

The previous prime is 999999987761. The next prime is 999999987827. The reversal of 999999987787 is 787789999999.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 999999987787 - 2¹¹ = 999999985739 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 999999987692 and 999999987701.

It is not a weakly prime, because it can be changed into another prime (999999187787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499999993893 + 499999993894.

It is an arithmetic number, because the mean of its divisors is an integer number (499999993894).

Almost surely, 2^999999987787 is an apocalyptic number.

999999987787 is a deficient number, since it is larger than the sum of its proper divisors (1).

999999987787 is an equidigital number, since it uses as much as digits as its factorization.

999999987787 is an evil number, because the sum of its binary digits is even.

The product of its digits is 104995735488, while the sum is 100.

The spelling of 999999987787 in words is "nine hundred ninety-nine billion, nine hundred ninety-nine million, nine hundred eighty-seven thousand, seven hundred eighty-seven".