1221513204252 has 24 divisors (see below), whose sum is σ = 3109306338432. Its totient is φ = 370155516400.

The previous prime is 1221513204211. The next prime is 1221513204257. The reversal of 1221513204252 is 2524023151221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221513204257) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4626943824 + ... + 4626944087.

It is an arithmetic number, because the mean of its divisors is an integer number (129554430768).

Almost surely, 2^{1221513204252} is an apocalyptic number.

1221513204252 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1221513204252 is an abundant number, since it is smaller than the sum of its proper divisors (1887793134180).

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

1221513204252 is a wasteful number, since it uses less digits than its factorization.

1221513204252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9253887929 (or 9253887927 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 30.

Adding to 1221513204252 its reverse (2524023151221), we get a palindrome (3745536355473).

The spelling of 1221513204252 in words is "one trillion, two hundred twenty-one billion, five hundred thirteen million, two hundred four thousand, two hundred fifty-two".