2040040021 has 2 divisors, whose sum is σ = 2040040022. Its totient is φ = 2040040020.

The previous prime is 2040040007. The next prime is 2040040073. The reversal of 2040040021 is 1200400402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1994962225 + 45077796 = 44665^2 + 6714^2 .

It is a cyclic number.

It is not a de Polignac number, because 2040040021 - 2⁷ = 2040039893 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2040039983 and 2040040010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2040040421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1020020010 + 1020020011.

It is an arithmetic number, because the mean of its divisors is an integer number (1020020011).

Almost surely, 2^2040040021 is an apocalyptic number.

It is an amenable number.

2040040021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2040040021 is an equidigital number, since it uses as much as digits as its factorization.

2040040021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 13.

The square root of 2040040021 is about 45166.8022002887. The cubic root of 2040040021 is about 1268.2734346893.

Adding to 2040040021 its reverse (1200400402), we get a palindrome (3240440423).

The spelling of 2040040021 in words is "two billion, forty million, forty thousand, twenty-one".