1151021221 has 8 divisors (see below), whose sum is σ = 1342299200. Its totient is φ = 986589324.

The previous prime is 1151021219. The next prime is 1151021239. The reversal of 1151021221 is 1221201511.

It is not a de Polignac number, because 1151021221 - 2¹ = 1151021219 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1151021195 and 1151021204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1151021251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1677531 + ... + 1678216.

It is an arithmetic number, because the mean of its divisors is an integer number (167787400).

Almost surely, 2^1151021221 is an apocalyptic number.

It is an amenable number.

1151021221 is a deficient number, since it is larger than the sum of its proper divisors (191277979).

1151021221 is an frugal number, since it uses more digits than its factorization.

1151021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3355768 (or 3355754 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 16.

The square root of 1151021221 is about 33926.7036565594. The cubic root of 1151021221 is about 1047.9995839037. Note that the first 3 decimals are identical.

Adding to 1151021221 its reverse (1221201511), we get a palindrome (2372222732).

The spelling of 1151021221 in words is "one billion, one hundred fifty-one million, twenty-one thousand, two hundred twenty-one".