100120999991 has 2 divisors, whose sum is σ = 100120999992. Its totient is φ = 100120999990.

The previous prime is 100120999981. The next prime is 100121000029. The reversal of 100120999991 is 199999021001.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-100120999991 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100120999981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50060499995 + 50060499996.

It is an arithmetic number, because the mean of its divisors is an integer number (50060499996).

Almost surely, 2^100120999991 is an apocalyptic number.

100120999991 is a deficient number, since it is larger than the sum of its proper divisors (1).

100120999991 is an equidigital number, since it uses as much as digits as its factorization.

100120999991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 118098, while the sum is 50.

The spelling of 100120999991 in words is "one hundred billion, one hundred twenty million, nine hundred ninety-nine thousand, nine hundred ninety-one".