1213545121 has 2 divisors, whose sum is σ = 1213545122. Its totient is φ = 1213545120.

The previous prime is 1213545037. The next prime is 1213545131. The reversal of 1213545121 is 1215453121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 857845521 + 355699600 = 29289^2 + 18860^2 .

It is a cyclic number.

It is not a de Polignac number, because 1213545121 - 2¹¹ = 1213543073 is a prime.

It is not a weakly prime, because it can be changed into another prime (1213545131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606772560 + 606772561.

It is an arithmetic number, because the mean of its divisors is an integer number (606772561).

Almost surely, 2^1213545121 is an apocalyptic number.

It is an amenable number.

1213545121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1213545121 is an equidigital number, since it uses as much as digits as its factorization.

1213545121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1200, while the sum is 25.

The square root of 1213545121 is about 34835.9745234721. The cubic root of 1213545121 is about 1066.6419077044.

Adding to 1213545121 its reverse (1215453121), we get a palindrome (2428998242).

The spelling of 1213545121 in words is "one billion, two hundred thirteen million, five hundred forty-five thousand, one hundred twenty-one".