1151232221 has 4 divisors (see below), whose sum is σ = 1155388572. Its totient is φ = 1147075872.

The previous prime is 1151232217. The next prime is 1151232289. The reversal of 1151232221 is 1222321511.

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 526932025 + 624300196 = 22955^2 + 24986^2 .

It is a cyclic number.

It is not a de Polignac number, because 1151232221 - 2² = 1151232217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1151232193 and 1151232202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1151432221) 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, 2077760 + ... + 2078313.

It is an arithmetic number, because the mean of its divisors is an integer number (288847143).

Almost surely, 2^1151232221 is an apocalyptic number.

It is an amenable number.

1151232221 is a deficient number, since it is larger than the sum of its proper divisors (4156351).

1151232221 is an equidigital number, since it uses as much as digits as its factorization.

1151232221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4156350.

The product of its digits is 240, while the sum is 20.

The square root of 1151232221 is about 33929.8131589315. The cubic root of 1151232221 is about 1048.0636181710.

Adding to 1151232221 its reverse (1222321511), we get a palindrome (2373553732).

The spelling of 1151232221 in words is "one billion, one hundred fifty-one million, two hundred thirty-two thousand, two hundred twenty-one".