1023440021 has 2 divisors, whose sum is σ = 1023440022. Its totient is φ = 1023440020.

The previous prime is 1023440009. The next prime is 1023440027. The reversal of 1023440021 is 1200443201.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 720331921 + 303108100 = 26839^2 + 17410^2 .

It is a cyclic number.

It is not a de Polignac number, because 1023440021 - 2²⁶ = 956331157 is a prime.

It is a super-3 number, since 3×1023440021³ (a number of 28 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1023440027) 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 as a sum of consecutive naturals, namely, 511720010 + 511720011.

It is an arithmetic number, because the mean of its divisors is an integer number (511720011).

Almost surely, 2^1023440021 is an apocalyptic number.

It is an amenable number.

1023440021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1023440021 is an equidigital number, since it uses as much as digits as its factorization.

1023440021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 1023440021 is about 31991.2491315985. The cubic root of 1023440021 is about 1007.7530748180.

Adding to 1023440021 its reverse (1200443201), we get a palindrome (2223883222).

The spelling of 1023440021 in words is "one billion, twenty-three million, four hundred forty thousand, twenty-one".