1154221221 has 4 divisors (see below), whose sum is σ = 1538961632. Its totient is φ = 769480812.

The previous prime is 1154221207. The next prime is 1154221223. The reversal of 1154221221 is 1221224511.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1154221221 - 2⁹ = 1154220709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1154221223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 192370201 + ... + 192370206.

It is an arithmetic number, because the mean of its divisors is an integer number (384740408).

Almost surely, 2^1154221221 is an apocalyptic number.

It is an amenable number.

1154221221 is a deficient number, since it is larger than the sum of its proper divisors (384740411).

1154221221 is an equidigital number, since it uses as much as digits as its factorization.

1154221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 384740410.

The product of its digits is 320, while the sum is 21.

The square root of 1154221221 is about 33973.8314147816. The cubic root of 1154221221 is about 1048.9698804179.

Adding to 1154221221 its reverse (1221224511), we get a palindrome (2375445732).

The spelling of 1154221221 in words is "one billion, one hundred fifty-four million, two hundred twenty-one thousand, two hundred twenty-one".