1001331221 has 4 divisors (see below), whose sum is σ = 1092361344. Its totient is φ = 910301100.

The previous prime is 1001331211. The next prime is 1001331223. The reversal of 1001331221 is 1221331001.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1001331221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1001331196 and 1001331205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001331223) 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 3 ways as a sum of consecutive naturals, for example, 45515045 + ... + 45515066.

It is an arithmetic number, because the mean of its divisors is an integer number (273090336).

Almost surely, 2^1001331221 is an apocalyptic number.

1001331221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1001331221 is a deficient number, since it is larger than the sum of its proper divisors (91030123).

1001331221 is an equidigital number, since it uses as much as digits as its factorization.

1001331221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91030122.

The product of its (nonzero) digits is 36, while the sum is 14.

The square root of 1001331221 is about 31643.8180534524. The cubic root of 1001331221 is about 1000.4435435733.

Adding to 1001331221 its reverse (1221331001), we get a palindrome (2222662222).

The spelling of 1001331221 in words is "one billion, one million, three hundred thirty-one thousand, two hundred twenty-one".