1221044577720 has 64 divisors (see below), whose sum is σ = 3996145895040. Its totient is φ = 296010806400.

The previous prime is 1221044577679. The next prime is 1221044577721. The reversal of 1221044577720 is 277754401221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221044577721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 462515566 + ... + 462518205.

It is an arithmetic number, because the mean of its divisors is an integer number (62439779610).

Almost surely, 2^{1221044577720} is an apocalyptic number.

1221044577720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221044577720 is an abundant number, since it is smaller than the sum of its proper divisors (2775101317320).

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

1221044577720 is a wasteful number, since it uses less digits than its factorization.

1221044577720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 925033796 (or 925033792 counting only the distinct ones).

The product of its (nonzero) digits is 219520, while the sum is 42.

Adding to 1221044577720 its reverse (277754401221), we get a palindrome (1498798978941).

The spelling of 1221044577720 in words is "one trillion, two hundred twenty-one billion, forty-four million, five hundred seventy-seven thousand, seven hundred twenty".