6390521 has 8 divisors (see below), whose sum is σ = 6793704. Its totient is φ = 5990400.

The previous prime is 6390499. The next prime is 6390533. The reversal of 6390521 is 1250936.

It can be written as a sum of positive squares in 4 ways, for example, as 215296 + 6175225 = 464^2 + 2485^2 .

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-6390521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6390541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4721 + ... + 5921.

It is an arithmetic number, because the mean of its divisors is an integer number (849213).

Almost surely, 2^6390521 is an apocalyptic number.

It is an amenable number.

6390521 is a deficient number, since it is larger than the sum of its proper divisors (403183).

6390521 is a wasteful number, since it uses less digits than its factorization.

6390521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1531.

The product of its (nonzero) digits is 1620, while the sum is 26.

The square root of 6390521 is about 2527.9479820598. The cubic root of 6390521 is about 185.5718463446.

The spelling of 6390521 in words is "six million, three hundred ninety thousand, five hundred twenty-one".