6390621 has 12 divisors (see below), whose sum is σ = 9272640. Its totient is φ = 4241160.

The previous prime is 6390611. The next prime is 6390641. The reversal of 6390621 is 1260936.

It is a happy number.

6390621 is a `hidden beast` number, since 6 + 39 + 0 + 621 = 666.

It is not a de Polignac number, because 6390621 - 2¹⁵ = 6357853 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6390611) 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 11 ways as a sum of consecutive naturals, for example, 666 + ... + 3636.

It is an arithmetic number, because the mean of its divisors is an integer number (772720).

Almost surely, 2^6390621 is an apocalyptic number.

It is an amenable number.

6390621 is a deficient number, since it is larger than the sum of its proper divisors (2882019).

6390621 is a wasteful number, since it uses less digits than its factorization.

6390621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3216 (or 3213 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The square root of 6390621 is about 2527.9677608704. The cubic root of 6390621 is about 185.5728142932.

The spelling of 6390621 in words is "six million, three hundred ninety thousand, six hundred twenty-one".