1001231221 has 16 divisors (see below), whose sum is σ = 1040212800. Its totient is φ = 963059328.

The previous prime is 1001231213. The next prime is 1001231237. The reversal of 1001231221 is 1221321001.

It is a cyclic number.

It is not a de Polignac number, because 1001231221 - 2³ = 1001231213 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 (1001231261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1518990 + ... + 1519648.

It is an arithmetic number, because the mean of its divisors is an integer number (65013300).

Almost surely, 2^1001231221 is an apocalyptic number.

It is an amenable number.

1001231221 is a deficient number, since it is larger than the sum of its proper divisors (38981579).

1001231221 is an equidigital number, since it uses as much as digits as its factorization.

1001231221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1188.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1001231221 is about 31642.2379265437. The cubic root of 1001231221 is about 1000.4102386812.

Adding to 1001231221 its reverse (1221321001), we get a palindrome (2222552222).

It can be divided in two parts, 100 and 1231221, that added together give a palindrome (1231321).

The spelling of 1001231221 in words is "one billion, one million, two hundred thirty-one thousand, two hundred twenty-one".