1000100115991 has 2 divisors, whose sum is σ = 1000100115992. Its totient is φ = 1000100115990.

The previous prime is 1000100115947. The next prime is 1000100116049. The reversal of 1000100115991 is 1995110010001.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1000100115991 - 2²⁷ = 999965898263 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1000100115901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500050057995 + 500050057996.

It is an arithmetic number, because the mean of its divisors is an integer number (500050057996).

Almost surely, 2^{1000100115991} is an apocalyptic number.

1000100115991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1000100115991 is an equidigital number, since it uses as much as digits as its factorization.

1000100115991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 405, while the sum is 28.

Adding to 1000100115991 its reverse (1995110010001), we get a palindrome (2995210125992).

The spelling of 1000100115991 in words is "one trillion, one hundred million, one hundred fifteen thousand, nine hundred ninety-one".