121221018 has 24 divisors (see below), whose sum is σ = 262918656. Its totient is φ = 40365000.

The previous prime is 121221013. The next prime is 121221019. The reversal of 121221018 is 810122121.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (121221013) 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 11 ways as a sum of consecutive naturals, for example, 17793 + ... + 23643.

It is an arithmetic number, because the mean of its divisors is an integer number (10954944).

Almost surely, 2^121221018 is an apocalyptic number.

121221018 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

121221018 is an abundant number, since it is smaller than the sum of its proper divisors (141697638).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

121221018 is a wasteful number, since it uses less digits than its factorization.

121221018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7010 (or 7007 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

The square root of 121221018 is about 11010.0416892944. The cubic root of 121221018 is about 494.9097111110.

Adding to 121221018 its reverse (810122121), we get a palindrome (931343139).

The spelling of 121221018 in words is "one hundred twenty-one million, two hundred twenty-one thousand, eighteen".