1221221111202 has 40 divisors (see below), whose sum is σ = 2736509437596. Its totient is φ = 407063359008.

The previous prime is 1221221111153. The next prime is 1221221111207. The reversal of 1221221111202 is 2021111221221.

It can be written as a sum of positive squares in 2 ways, for example, as 1176940747161 + 44280364041 = 1084869^2 + 210429^2 .

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

It is not an unprimeable number, because it can be changed into a prime (1221221111207) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 8895828 + ... + 9032064.

Almost surely, 2^{1221221111202} is an apocalyptic number.

1221221111202 is an abundant number, since it is smaller than the sum of its proper divisors (1515288326394).

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

1221221111202 is a wasteful number, since it uses less digits than its factorization.

1221221111202 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191584 (or 191575 counting only the distinct ones).

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

Adding to 1221221111202 its reverse (2021111221221), we get a palindrome (3242332332423).

The spelling of 1221221111202 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-one million, one hundred eleven thousand, two hundred two".