1155252121 has 9 divisors (see below), whose sum is σ = 1185546333. Its totient is φ = 1125715680.

The previous prime is 1155252067. The next prime is 1155252127. The reversal of 1155252121 is 1212525511.

It is a happy number.

The square root of 1155252121 is 33989.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 254051721 + 901200400 = 15939^2 + 30020^2 .

It is not a de Polignac number, because 1155252121 - 2¹¹ = 1155250073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1155252127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1393135 + ... + 1393963.

Almost surely, 2^1155252121 is an apocalyptic number.

1155252121 is the 33989-th square number.

1155252121 is the 16995-th centered octagonal number.

It is an amenable number.

1155252121 is a deficient number, since it is larger than the sum of its proper divisors (30294212).

1155252121 is an frugal number, since it uses more digits than its factorization.

1155252121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1740 (or 870 counting only the distinct ones).

The product of its digits is 1000, while the sum is 25.

The cubic root of 1155252121 is about 1049.2820855196.

Multiplying 1155252121 by its sum of digits (25), we get a square (28881303025 = 169945²).

Adding to 1155252121 its reverse (1212525511), we get a palindrome (2367777632).

The spelling of 1155252121 in words is "one billion, one hundred fifty-five million, two hundred fifty-two thousand, one hundred twenty-one".