121917811 has 8 divisors (see below), whose sum is σ = 123912704. Its totient is φ = 119931840.

The previous prime is 121917797. The next prime is 121917821. The reversal of 121917811 is 118719121.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 121917811 - 2¹¹ = 121915763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121917821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28750 + ... + 32716.

It is an arithmetic number, because the mean of its divisors is an integer number (15489088).

Almost surely, 2^121917811 is an apocalyptic number.

121917811 is a deficient number, since it is larger than the sum of its proper divisors (1994893).

121917811 is an equidigital number, since it uses as much as digits as its factorization.

121917811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4461.

The product of its digits is 1008, while the sum is 31.

The square root of 121917811 is about 11041.6398691499. The cubic root of 121917811 is about 495.8561668337.

It can be divided in two parts, 12191 and 7811, that added together give a palindrome (20002).

The spelling of 121917811 in words is "one hundred twenty-one million, nine hundred seventeen thousand, eight hundred eleven".