1155232121 has 2 divisors, whose sum is σ = 1155232122. Its totient is φ = 1155232120.

The previous prime is 1155232103. The next prime is 1155232147. The reversal of 1155232121 is 1212325511.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 736579600 + 418652521 = 27140^2 + 20461^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1155232121 is a prime.

It is a super-2 number, since 2×1155232121² = 2669122506780317282, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1155232171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 577616060 + 577616061.

It is an arithmetic number, because the mean of its divisors is an integer number (577616061).

Almost surely, 2^1155232121 is an apocalyptic number.

It is an amenable number.

1155232121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1155232121 is an equidigital number, since it uses as much as digits as its factorization.

1155232121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 600, while the sum is 23.

The square root of 1155232121 is about 33988.7057858931. The cubic root of 1155232121 is about 1049.2760303442.

Adding to 1155232121 its reverse (1212325511), we get a palindrome (2367557632).

The spelling of 1155232121 in words is "one billion, one hundred fifty-five million, two hundred thirty-two thousand, one hundred twenty-one".