121021218 has 24 divisors (see below), whose sum is σ = 262489968. Its totient is φ = 40297752.

The previous prime is 121021211. The next prime is 121021231. The reversal of 121021218 is 812120121.

It is a super-2 number, since 2×121021218² = 29292270412407048, which contains 22 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 121021218.

It is not an unprimeable number, because it can be changed into a prime (121021211) 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 11 ways as a sum of consecutive naturals, for example, 17221 + ... + 23207.

It is an arithmetic number, because the mean of its divisors is an integer number (10937082).

Almost surely, 2^121021218 is an apocalyptic number.

121021218 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

121021218 is an abundant number, since it is smaller than the sum of its proper divisors (141468750).

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

121021218 is a wasteful number, since it uses less digits than its factorization.

121021218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7118 (or 7115 counting only the distinct ones).

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

The square root of 121021218 is about 11000.9644122686. The cubic root of 121021218 is about 494.6376534019.

Adding to 121021218 its reverse (812120121), we get a palindrome (933141339).

The spelling of 121021218 in words is "one hundred twenty-one million, twenty-one thousand, two hundred eighteen".