1221021304308 has 216 divisors, whose sum is σ = 3493021371840. Its totient is φ = 358791713280.

The previous prime is 1221021304241. The next prime is 1221021304309. The reversal of 1221021304308 is 8034031201221.

1221021304308 is a `hidden beast` number, since 1 + 2 + 2 + 10 + 213 + 0 + 430 + 8 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221021304309) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 92208568 + ... + 92221808.

It is an arithmetic number, because the mean of its divisors is an integer number (16171395240).

Almost surely, 2^{1221021304308} is an apocalyptic number.

1221021304308 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221021304308, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1746510685920).

1221021304308 is an abundant number, since it is smaller than the sum of its proper divisors (2272000067532).

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

1221021304308 is a wasteful number, since it uses less digits than its factorization.

1221021304308 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13959 (or 13941 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

Adding to 1221021304308 its reverse (8034031201221), we get a palindrome (9255052505529).

The spelling of 1221021304308 in words is "one trillion, two hundred twenty-one billion, twenty-one million, three hundred four thousand, three hundred eight".