6521009 has 16 divisors (see below), whose sum is σ = 7680960. Its totient is φ = 5472000.

The previous prime is 6521003. The next prime is 6521023. The reversal of 6521009 is 9001256.

6521009 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 6521009 - 2¹⁶ = 6455473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6521003) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8189 + ... + 8949.

It is an arithmetic number, because the mean of its divisors is an integer number (480060).

Almost surely, 2^6521009 is an apocalyptic number.

It is an amenable number.

6521009 is a deficient number, since it is larger than the sum of its proper divisors (1159951).

6521009 is a wasteful number, since it uses less digits than its factorization.

6521009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 832.

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 6521009 is about 2553.6266367658. The cubic root of 6521009 is about 186.8264091068.

It can be divided in two parts, 652 and 1009, that added together give a palindrome (1661).

The spelling of 6521009 in words is "six million, five hundred twenty-one thousand, nine".