1221211220022 has 64 divisors (see below), whose sum is σ = 2871135590400. Its totient is φ = 383687992800.

The previous prime is 1221211219997. The next prime is 1221211220029. The reversal of 1221211220022 is 2200221121221.

It is a happy number.

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 = 1221211219977 and 1221211220004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221211220029) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2818854 + ... + 3223097.

It is an arithmetic number, because the mean of its divisors is an integer number (44861493600).

Almost surely, 2^{1221211220022} is an apocalyptic number.

1221211220022 is an abundant number, since it is smaller than the sum of its proper divisors (1649924370378).

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

1221211220022 is a wasteful number, since it uses less digits than its factorization.

1221211220022 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6042178 (or 6042172 counting only the distinct ones).

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

Adding to 1221211220022 its reverse (2200221121221), we get a palindrome (3421432341243).

The spelling of 1221211220022 in words is "one trillion, two hundred twenty-one billion, two hundred eleven million, two hundred twenty thousand, twenty-two".