1155524221 has 4 divisors (see below), whose sum is σ = 1223496252. Its totient is φ = 1087552192.

The previous prime is 1155524207. The next prime is 1155524261. The reversal of 1155524221 is 1224255511.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1076758596 + 78765625 = 32814^2 + 8875^2 .

It is a cyclic number.

It is not a de Polignac number, because 1155524221 - 2⁵ = 1155524189 is a prime.

It is a super-3 number, since 3×1155524221³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1155524221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1155524261) 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, 33985990 + ... + 33986023.

It is an arithmetic number, because the mean of its divisors is an integer number (305874063).

Almost surely, 2^1155524221 is an apocalyptic number.

It is an amenable number.

1155524221 is a deficient number, since it is larger than the sum of its proper divisors (67972031).

1155524221 is an equidigital number, since it uses as much as digits as its factorization.

1155524221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67972030.

The product of its digits is 4000, while the sum is 28.

The square root of 1155524221 is about 33993.0025299325. The cubic root of 1155524221 is about 1049.3644592392.

Adding to 1155524221 its reverse (1224255511), we get a palindrome (2379779732).

The spelling of 1155524221 in words is "one billion, one hundred fifty-five million, five hundred twenty-four thousand, two hundred twenty-one".