121221220212 has 18 divisors (see below), whose sum is σ = 306420306738. Its totient is φ = 40407073392.

The previous prime is 121221220189. The next prime is 121221220213. The reversal of 121221220212 is 212022122121.

It is a happy number.

121221220212 is a `hidden beast` number, since 1 + 212 + 21 + 220 + 212 = 666.

It can be written as a sum of positive squares in only one way, i.e., 86555993616 + 34665226596 = 294204^2 + 186186^2 .

It is a tau number, because it is divible by the number of its divisors (18).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121221220213) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1683628023 + ... + 1683628094.

Almost surely, 2^121221220212 is an apocalyptic number.

121221220212 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

121221220212 is an abundant number, since it is smaller than the sum of its proper divisors (185199086526).

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

121221220212 is a wasteful number, since it uses less digits than its factorization.

121221220212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3367256127 (or 3367256122 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 121221220212 its reverse (212022122121), we get a palindrome (333243342333).

The spelling of 121221220212 in words is "one hundred twenty-one billion, two hundred twenty-one million, two hundred twenty thousand, two hundred twelve".