4009021 has 8 divisors (see below), whose sum is σ = 4133304. Its totient is φ = 3886080.

The previous prime is 4009007. The next prime is 4009037. The reversal of 4009021 is 1209004.

It can be written as a sum of positive squares in 4 ways, for example, as 52900 + 3956121 = 230^2 + 1989^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-4009021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 4008986 and 4009004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4009001) 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 in 7 ways as a sum of consecutive naturals, for example, 11181 + ... + 11533.

It is an arithmetic number, because the mean of its divisors is an integer number (516663).

Almost surely, 2^4009021 is an apocalyptic number.

4009021 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

It is an amenable number.

4009021 is a deficient number, since it is larger than the sum of its proper divisors (124283).

4009021 is a wasteful number, since it uses less digits than its factorization.

4009021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 671.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 4009021 is about 2002.2539798937. The cubic root of 4009021 is about 158.8593484746.

The spelling of 4009021 in words is "four million, nine thousand, twenty-one".