1213543555 has 24 divisors (see below), whose sum is σ = 1793661408. Its totient is φ = 783191808.

The previous prime is 1213543511. The next prime is 1213543561. The reversal of 1213543555 is 5553453121.

It is not a de Polignac number, because 1213543555 - 2¹¹ = 1213541507 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1213543555.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 141519 + ... + 149848.

It is an arithmetic number, because the mean of its divisors is an integer number (74735892).

Almost surely, 2^1213543555 is an apocalyptic number.

1213543555 is a deficient number, since it is larger than the sum of its proper divisors (580117853).

1213543555 is a wasteful number, since it uses less digits than its factorization.

1213543555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291403 (or 291396 counting only the distinct ones).

The product of its digits is 45000, while the sum is 34.

The square root of 1213543555 is about 34835.9520467003. The cubic root of 1213543555 is about 1066.6414488938.

Adding to 1213543555 its reverse (5553453121), we get a palindrome (6766996676).

The spelling of 1213543555 in words is "one billion, two hundred thirteen million, five hundred forty-three thousand, five hundred fifty-five".