1213165553 has 2 divisors, whose sum is σ = 1213165554. Its totient is φ = 1213165552.

The previous prime is 1213165549. The next prime is 1213165573. The reversal of 1213165553 is 3555613121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 976375009 + 236790544 = 31247^2 + 15388^2 .

It is a cyclic number.

It is not a de Polignac number, because 1213165553 - 2² = 1213165549 is a prime.

It is not a weakly prime, because it can be changed into another prime (1213165573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606582776 + 606582777.

It is an arithmetic number, because the mean of its divisors is an integer number (606582777).

Almost surely, 2^1213165553 is an apocalyptic number.

It is an amenable number.

1213165553 is a deficient number, since it is larger than the sum of its proper divisors (1).

1213165553 is an equidigital number, since it uses as much as digits as its factorization.

1213165553 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13500, while the sum is 32.

The square root of 1213165553 is about 34830.5261659941. The cubic root of 1213165553 is about 1066.5306893831.

Adding to 1213165553 its reverse (3555613121), we get a palindrome (4768778674).

The spelling of 1213165553 in words is "one billion, two hundred thirteen million, one hundred sixty-five thousand, five hundred fifty-three".