121811866 has 8 divisors (see below), whose sum is σ = 199328544. Its totient is φ = 55369020.

The previous prime is 121811857. The next prime is 121811867. The reversal of 121811866 is 668118121.

It is a happy number.

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

It is not an unprimeable number, because it can be changed into a prime (121811867) 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, 2768430 + ... + 2768473.

It is an arithmetic number, because the mean of its divisors is an integer number (24916068).

Almost surely, 2^121811866 is an apocalyptic number.

121811866 is a deficient number, since it is larger than the sum of its proper divisors (77516678).

121811866 is a wasteful number, since it uses less digits than its factorization.

121811866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5536916.

The product of its digits is 4608, while the sum is 34.

The square root of 121811866 is about 11036.8413053736. The cubic root of 121811866 is about 495.7124943451.

Adding to 121811866 its reverse (668118121), we get a palindrome (789929987).

The spelling of 121811866 in words is "one hundred twenty-one million, eight hundred eleven thousand, eight hundred sixty-six".