1155331213 has 4 divisors (see below), whose sum is σ = 1156336128. Its totient is φ = 1154326300.

The previous prime is 1155331201. The next prime is 1155331279. The reversal of 1155331213 is 3121335511.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1155331213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1155331813) 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, 500731 + ... + 503032.

It is an arithmetic number, because the mean of its divisors is an integer number (289084032).

Almost surely, 2^1155331213 is an apocalyptic number.

It is an amenable number.

1155331213 is a deficient number, since it is larger than the sum of its proper divisors (1004915).

1155331213 is a wasteful number, since it uses less digits than its factorization.

1155331213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1004914.

The product of its digits is 1350, while the sum is 25.

The square root of 1155331213 is about 33990.1634741582. The cubic root of 1155331213 is about 1049.3060306318.

Adding to 1155331213 its reverse (3121335511), we get a palindrome (4276666724).

The spelling of 1155331213 in words is "one billion, one hundred fifty-five million, three hundred thirty-one thousand, two hundred thirteen".