1001440021 has 2 divisors, whose sum is σ = 1001440022. Its totient is φ = 1001440020.

The previous prime is 1001439983. The next prime is 1001440067. The reversal of 1001440021 is 1200441001.

1001440021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 817159396 + 184280625 = 28586^2 + 13575^2 .

It is a cyclic number.

It is not a de Polignac number, because 1001440021 - 2¹¹ = 1001437973 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1001439983 and 1001440010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1001440081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500720010 + 500720011.

It is an arithmetic number, because the mean of its divisors is an integer number (500720011).

Almost surely, 2^1001440021 is an apocalyptic number.

It is an amenable number.

1001440021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1001440021 is an equidigital number, since it uses as much as digits as its factorization.

1001440021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 1001440021 is about 31645.5371419099. The cubic root of 1001440021 is about 1000.4797767774.

Adding to 1001440021 its reverse (1200441001), we get a palindrome (2201881022).

The spelling of 1001440021 in words is "one billion, one million, four hundred forty thousand, twenty-one".