121991908001 has 4 divisors (see below), whose sum is σ = 122137310400. Its totient is φ = 121846505604.

The previous prime is 121991907959. The next prime is 121991908007. The reversal of 121991908001 is 100809199121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 121991908001 - 2²⁶ = 121924799137 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 121991908001.

It is not an unprimeable number, because it can be changed into a prime (121991908007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72699941 + ... + 72701618.

It is an arithmetic number, because the mean of its divisors is an integer number (30534327600).

Almost surely, 2^121991908001 is an apocalyptic number.

It is an amenable number.

121991908001 is a deficient number, since it is larger than the sum of its proper divisors (145402399).

121991908001 is an equidigital number, since it uses as much as digits as its factorization.

121991908001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145402398.

The product of its (nonzero) digits is 11664, while the sum is 41.

The spelling of 121991908001 in words is "one hundred twenty-one billion, nine hundred ninety-one million, nine hundred eight thousand, one".