4004012021 has 2 divisors, whose sum is σ = 4004012022. Its totient is φ = 4004012020.

The previous prime is 4004011961. The next prime is 4004012027. The reversal of 4004012021 is 1202104004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2896054225 + 1107957796 = 53815^2 + 33286^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-4004012021 is a prime.

It is a super-2 number, since 2×4004012021² = 32064224528625008882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 4004011987 and 4004012005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4004012027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2002006010 + 2002006011.

It is an arithmetic number, because the mean of its divisors is an integer number (2002006011).

Almost surely, 2^4004012021 is an apocalyptic number.

It is an amenable number.

4004012021 is a deficient number, since it is larger than the sum of its proper divisors (1).

4004012021 is an equidigital number, since it uses as much as digits as its factorization.

4004012021 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 14.

The square root of 4004012021 is about 63277.2630650220. The cubic root of 4004012021 is about 1587.9315984904.

Adding to 4004012021 its reverse (1202104004), we get a palindrome (5206116025).

The spelling of 4004012021 in words is "four billion, four million, twelve thousand, twenty-one".