4007021 has 2 divisors, whose sum is σ = 4007022. Its totient is φ = 4007020.

The previous prime is 4006993. The next prime is 4007023. The reversal of 4007021 is 1207004.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3222025 + 784996 = 1795^2 + 886^2 .

It is a cyclic number.

It is not a de Polignac number, because 4007021 - 2⁶ = 4006957 is a prime.

Together with 4007023, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 4006987 and 4007005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4007023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2003510 + 2003511.

It is an arithmetic number, because the mean of its divisors is an integer number (2003511).

Almost surely, 2^4007021 is an apocalyptic number.

It is an amenable number.

4007021 is a deficient number, since it is larger than the sum of its proper divisors (1).

4007021 is an equidigital number, since it uses as much as digits as its factorization.

4007021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56, while the sum is 14.

The square root of 4007021 is about 2001.7544804496. The cubic root of 4007021 is about 158.8329270993.

The spelling of 4007021 in words is "four million, seven thousand, twenty-one".