1213545563 has 4 divisors (see below), whose sum is σ = 1226056440. Its totient is φ = 1201034688.

The previous prime is 1213545559. The next prime is 1213545569. The reversal of 1213545563 is 3655453121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1213545563 - 2² = 1213545559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1213545569) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6255293 + ... + 6255486.

It is an arithmetic number, because the mean of its divisors is an integer number (306514110).

Almost surely, 2^1213545563 is an apocalyptic number.

1213545563 is a deficient number, since it is larger than the sum of its proper divisors (12510877).

1213545563 is an equidigital number, since it uses as much as digits as its factorization.

1213545563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12510876.

The product of its digits is 54000, while the sum is 35.

The square root of 1213545563 is about 34835.9808674881. The cubic root of 1213545563 is about 1066.6420372026.

Adding to 1213545563 its reverse (3655453121), we get a palindrome (4868998684).

The spelling of 1213545563 in words is "one billion, two hundred thirteen million, five hundred forty-five thousand, five hundred sixty-three".