1243203400221 has 16 divisors (see below), whose sum is σ = 1711298764800. Its totient is φ = 801962123760.

The previous prime is 1243203400217. The next prime is 1243203400247. The reversal of 1243203400221 is 1220043023421.

It is a happy number.

It is not a de Polignac number, because 1243203400221 - 2² = 1243203400217 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1243203400191 and 1243203400200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1243203400321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 151321 + ... + 1584078.

It is an arithmetic number, because the mean of its divisors is an integer number (106956172800).

Almost surely, 2^{1243203400221} is an apocalyptic number.

It is an amenable number.

1243203400221 is a deficient number, since it is larger than the sum of its proper divisors (468095364579).

1243203400221 is a wasteful number, since it uses less digits than its factorization.

1243203400221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1743136.

The product of its (nonzero) digits is 2304, while the sum is 24.

Adding to 1243203400221 its reverse (1220043023421), we get a palindrome (2463246423642).

The spelling of 1243203400221 in words is "one trillion, two hundred forty-three billion, two hundred three million, four hundred thousand, two hundred twenty-one".