1221503222016 has 648 divisors, whose sum is σ = 4704662944800. Its totient is φ = 300569149440.

The previous prime is 1221503221993. The next prime is 1221503222119. The reversal of 1221503222016 is 6102223051221.

1221503222016 is a `hidden beast` number, since 122 + 1 + 503 + 2 + 2 + 20 + 16 = 666.

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, 23569380 + ... + 23621148.

Almost surely, 2^{1221503222016} is an apocalyptic number.

1221503222016 is a gapful number since it is divisible by the number (16) 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 1221503222016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2352331472400).

1221503222016 is an abundant number, since it is smaller than the sum of its proper divisors (3483159722784).

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

1221503222016 is a wasteful number, since it uses less digits than its factorization.

1221503222016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51835 (or 51811 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

Adding to 1221503222016 its reverse (6102223051221), we get a palindrome (7323726273237).

The spelling of 1221503222016 in words is "one trillion, two hundred twenty-one billion, five hundred three million, two hundred twenty-two thousand, sixteen".