1221221022102 has 96 divisors (see below), whose sum is σ = 2777627492640. Its totient is φ = 402091050240.

The previous prime is 1221221022101. The next prime is 1221221022107. The reversal of 1221221022102 is 2012201221221.

It is a happy number.

1221221022102 is a `hidden beast` number, since 1 + 221 + 221 + 0 + 221 + 0 + 2 = 666.

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 (1221221022101) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 44148508 + ... + 44176160.

It is an arithmetic number, because the mean of its divisors is an integer number (28933619715).

Almost surely, 2^{1221221022102} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221221022102, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1388813746320).

1221221022102 is an abundant number, since it is smaller than the sum of its proper divisors (1556406470538).

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

1221221022102 is a wasteful number, since it uses less digits than its factorization.

1221221022102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28780 (or 28768 counting only the distinct ones).

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

Adding to 1221221022102 its reverse (2012201221221), we get a palindrome (3233422243323).

The spelling of 1221221022102 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-one million, twenty-two thousand, one hundred two".