1001001221 has 8 divisors (see below), whose sum is σ = 1099332000. Its totient is φ = 903892240.

The previous prime is 1001001217. The next prime is 1001001223. The reversal of 1001001221 is 1221001001.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1001001221 - 2² = 1001001217 is a prime.

It is a Duffinian number.

1001001221 is a modest number, since divided by 1221 gives 1001 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 1001001199 and 1001001208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001001223) 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, 303731 + ... + 307008.

It is an arithmetic number, because the mean of its divisors is an integer number (137416500).

Almost surely, 2^1001001221 is an apocalyptic number.

1001001221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1001001221 is a deficient number, since it is larger than the sum of its proper divisors (98330779).

1001001221 is a wasteful number, since it uses less digits than its factorization.

1001001221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 610899.

The product of its (nonzero) digits is 4, while the sum is 8.

The square root of 1001001221 is about 31638.6033351664. The cubic root of 1001001221 is about 1000.3336290126. Note that the first 3 decimals are identical.

Adding to 1001001221 its reverse (1221001001), we get a palindrome (2222002222).

The spelling of 1001001221 in words is "one billion, one million, one thousand, two hundred twenty-one".