99999199987 has 2 divisors, whose sum is σ = 99999199988. Its totient is φ = 99999199986.

The previous prime is 99999199973. The next prime is 99999199999. The reversal of 99999199987 is 78999199999.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99999199987 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 99999199898 and 99999199907.

It is not a weakly prime, because it can be changed into another prime (99999199387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49999599993 + 49999599994.

It is an arithmetic number, because the mean of its divisors is an integer number (49999599994).

Almost surely, 2^99999199987 is an apocalyptic number.

99999199987 is a deficient number, since it is larger than the sum of its proper divisors (1).

99999199987 is an equidigital number, since it uses as much as digits as its factorization.

99999199987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2410616376, while the sum is 88.

The spelling of 99999199987 in words is "ninety-nine billion, nine hundred ninety-nine million, one hundred ninety-nine thousand, nine hundred eighty-seven".