1001223121 has 2 divisors, whose sum is σ = 1001223122. Its totient is φ = 1001223120.

The previous prime is 1001223079. The next prime is 1001223127. The reversal of 1001223121 is 1213221001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 989417025 + 11806096 = 31455^2 + 3436^2 .

It is a cyclic number.

It is not a de Polignac number, because 1001223121 - 2¹⁹ = 1000698833 is a prime.

It is not a weakly prime, because it can be changed into another prime (1001223127) 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 as a sum of consecutive naturals, namely, 500611560 + 500611561.

It is an arithmetic number, because the mean of its divisors is an integer number (500611561).

Almost surely, 2^1001223121 is an apocalyptic number.

It is an amenable number.

1001223121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1001223121 is an equidigital number, since it uses as much as digits as its factorization.

1001223121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1001223121 is about 31642.1099328095. The cubic root of 1001223121 is about 1000.4075408879.

Adding to 1001223121 its reverse (1213221001), we get a palindrome (2214444122).

It can be divided in two parts, 10012 and 23121, that added together give a palindrome (33133).

The spelling of 1001223121 in words is "one billion, one million, two hundred twenty-three thousand, one hundred twenty-one".