1155199221 has 72 divisors (see below), whose sum is σ = 1994021120. Its totient is φ = 641520000.

The previous prime is 1155199189. The next prime is 1155199223. The reversal of 1155199221 is 1229915511.

1155199221 is a `hidden beast` number, since 11 + 551 + 9 + 92 + 2 + 1 = 666.

It is not a de Polignac number, because 1155199221 - 2⁵ = 1155199189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1155199223) 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 in 71 ways as a sum of consecutive naturals, for example, 640521 + ... + 642321.

Almost surely, 2^1155199221 is an apocalyptic number.

1155199221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1155199221 is a deficient number, since it is larger than the sum of its proper divisors (838821899).

1155199221 is a wasteful number, since it uses less digits than its factorization.

1155199221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1879 (or 1865 counting only the distinct ones).

The product of its digits is 8100, while the sum is 36.

The square root of 1155199221 is about 33988.2217981465. The cubic root of 1155199221 is about 1049.2660694286.

The spelling of 1155199221 in words is "one billion, one hundred fifty-five million, one hundred ninety-nine thousand, two hundred twenty-one".