1221212201220 has 216 divisors, whose sum is σ = 4286018929920. Its totient is φ = 280469692800.

The previous prime is 1221212201197. The next prime is 1221212201233. The reversal of 1221212201220 is 221022121221.

It is a happy number.

1221212201220 is a `hidden beast` number, since 1 + 221 + 2 + 1 + 220 + 1 + 220 = 666.

It is a super-3 number, since 3×1221212201220³ (a number of 37 digits) contains 333 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 1221212201193 and 1221212201202.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1061716 + ... + 1889355.

Almost surely, 2^{1221212201220} is an apocalyptic number.

1221212201220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221212201220 is an abundant number, since it is smaller than the sum of its proper divisors (3064806728700).

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

1221212201220 is a wasteful number, since it uses less digits than its factorization.

1221212201220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2951127 (or 2951111 counting only the distinct ones).

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

Adding to 1221212201220 its reverse (221022121221), we get a palindrome (1442234322441).

The spelling of 1221212201220 in words is "one trillion, two hundred twenty-one billion, two hundred twelve million, two hundred one thousand, two hundred twenty".