4001009 has 2 divisors, whose sum is σ = 4001010. Its totient is φ = 4001008.

The previous prime is 4001003. The next prime is 4001017. The reversal of 4001009 is 9001004.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3888784 + 112225 = 1972^2 + 335^2 .

It is a cyclic number.

It is not a de Polignac number, because 4001009 - 2⁴ = 4000993 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 4000984 and 4001002.

It is not a weakly prime, because it can be changed into another prime (4001003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2000504 + 2000505.

It is an arithmetic number, because the mean of its divisors is an integer number (2000505).

Almost surely, 2^4001009 is an apocalyptic number.

It is an amenable number.

4001009 is a deficient number, since it is larger than the sum of its proper divisors (1).

4001009 is an equidigital number, since it uses as much as digits as its factorization.

4001009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 14.

The square root of 4001009 is about 2000.2522340945. The cubic root of 4001009 is about 158.7534514719.

The spelling of 4001009 in words is "four million, one thousand, nine".