1321001001 has 32 divisors (see below), whose sum is σ = 1977094400. Its totient is φ = 871689600.

The previous prime is 1321000981. The next prime is 1321001023. The reversal of 1321001001 is 1001001231.

It is not a de Polignac number, because 1321001001 - 2⁵ = 1321000969 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1321003001) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1862835 + ... + 1863543.

It is an arithmetic number, because the mean of its divisors is an integer number (61784200).

Almost surely, 2^1321001001 is an apocalyptic number.

It is an amenable number.

1321001001 is a deficient number, since it is larger than the sum of its proper divisors (656093399).

1321001001 is a wasteful number, since it uses less digits than its factorization.

1321001001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1326 (or 1320 counting only the distinct ones).

The product of its (nonzero) digits is 6, while the sum is 9.

The square root of 1321001001 is about 36345.5774613639. The cubic root of 1321001001 is about 1097.2385281432.

Adding to 1321001001 its reverse (1001001231), we get a palindrome (2322002232).

The spelling of 1321001001 in words is "one billion, three hundred twenty-one million, one thousand, one".