121856202011 has 4 divisors (see below), whose sum is σ = 129024213912. Its totient is φ = 114688190112.

The previous prime is 121856201989. The next prime is 121856202047. The reversal of 121856202011 is 110202658121.

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 121856202011 - 2¹⁰ = 121856200987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121856202911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3584005925 + ... + 3584005958.

It is an arithmetic number, because the mean of its divisors is an integer number (32256053478).

Almost surely, 2^121856202011 is an apocalyptic number.

121856202011 is a deficient number, since it is larger than the sum of its proper divisors (7168011901).

121856202011 is an equidigital number, since it uses as much as digits as its factorization.

121856202011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7168011900.

The product of its (nonzero) digits is 1920, while the sum is 29.

The spelling of 121856202011 in words is "one hundred twenty-one billion, eight hundred fifty-six million, two hundred two thousand, eleven".