100121009999 has 4 divisors (see below), whose sum is σ = 100148724936. Its totient is φ = 100093295064.

The previous prime is 100121009987. The next prime is 100121010019. The reversal of 100121009999 is 999900121001.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 100121009999 - 2¹⁶ = 100120944463 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100121009909) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13852049 + ... + 13859274.

It is an arithmetic number, because the mean of its divisors is an integer number (25037181234).

Almost surely, 2^100121009999 is an apocalyptic number.

100121009999 is a deficient number, since it is larger than the sum of its proper divisors (27714937).

100121009999 is an equidigital number, since it uses as much as digits as its factorization.

100121009999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27714936.

The product of its (nonzero) digits is 13122, while the sum is 41.

The spelling of 100121009999 in words is "one hundred billion, one hundred twenty-one million, nine thousand, nine hundred ninety-nine".