1221354344500 has 24 divisors (see below), whose sum is σ = 2667437889480. Its totient is φ = 488541737600.

The previous prime is 1221354344491. The next prime is 1221354344521. The reversal of 1221354344500 is 54434531221.

It can be written as a sum of positive squares in 4 ways, for example, as 13052148516 + 1208302195984 = 114246^2 + 1099228^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1221353845 + ... + 1221354844.

It is an arithmetic number, because the mean of its divisors is an integer number (111143245395).

Almost surely, 2^{1221354344500} is an apocalyptic number.

1221354344500 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221354344500 is an abundant number, since it is smaller than the sum of its proper divisors (1446083544980).

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

1221354344500 is a wasteful number, since it uses less digits than its factorization.

1221354344500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2442708708 (or 2442708696 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 34.

Adding to 1221354344500 its reverse (54434531221), we get a palindrome (1275788875721).

The spelling of 1221354344500 in words is "one trillion, two hundred twenty-one billion, three hundred fifty-four million, three hundred forty-four thousand, five hundred".