1200002231921 has 2 divisors, whose sum is σ = 1200002231922. Its totient is φ = 1200002231920.

The previous prime is 1200002231887. The next prime is 1200002232029. The reversal of 1200002231921 is 1291322000021.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1056966991921 + 143035240000 = 1028089^2 + 378200^2 .

It is an emirp because it is prime and its reverse (1291322000021) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1200002231921 is a prime.

It is not a weakly prime, because it can be changed into another prime (1200002231321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 600001115960 + 600001115961.

It is an arithmetic number, because the mean of its divisors is an integer number (600001115961).

Almost surely, 2^{1200002231921} is an apocalyptic number.

It is an amenable number.

1200002231921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1200002231921 is an equidigital number, since it uses as much as digits as its factorization.

1200002231921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 23.

Adding to 1200002231921 its reverse (1291322000021), we get a palindrome (2491324231942).

The spelling of 1200002231921 in words is "one trillion, two hundred billion, two million, two hundred thirty-one thousand, nine hundred twenty-one".