1213361555 has 16 divisors (see below), whose sum is σ = 1673241024. Its totient is φ = 827418240.

The previous prime is 1213361551. The next prime is 1213361561. The reversal of 1213361555 is 5551633121.

It is not a de Polignac number, because 1213361555 - 2² = 1213361551 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1213361551) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 89432 + ... + 102101.

It is an arithmetic number, because the mean of its divisors is an integer number (104577564).

Almost surely, 2^1213361555 is an apocalyptic number.

1213361555 is a deficient number, since it is larger than the sum of its proper divisors (459879469).

1213361555 is a wasteful number, since it uses less digits than its factorization.

1213361555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191726.

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

The square root of 1213361555 is about 34833.3397049436. The cubic root of 1213361555 is about 1066.5881233942.

Adding to 1213361555 its reverse (5551633121), we get a palindrome (6764994676).

The spelling of 1213361555 in words is "one billion, two hundred thirteen million, three hundred sixty-one thousand, five hundred fifty-five".