6490021 has 4 divisors (see below), whose sum is σ = 6515532. Its totient is φ = 6464512.

The previous prime is 6490007. The next prime is 6490027. The reversal of 6490021 is 1200946.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6305121 + 184900 = 2511^2 + 430^2 .

It is a cyclic number.

It is not a de Polignac number, because 6490021 - 2⁷ = 6489893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6489974 and 6490001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6490027) 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 3 ways as a sum of consecutive naturals, for example, 12370 + ... + 12883.

It is an arithmetic number, because the mean of its divisors is an integer number (1628883).

Almost surely, 2^6490021 is an apocalyptic number.

It is an amenable number.

6490021 is a deficient number, since it is larger than the sum of its proper divisors (25511).

6490021 is a wasteful number, since it uses less digits than its factorization.

6490021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25510.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 6490021 is about 2547.5519621786. The cubic root of 6490021 is about 186.5300044924.

Adding to 6490021 its reverse (1200946), we get a palindrome (7690967).

The spelling of 6490021 in words is "six million, four hundred ninety thousand, twenty-one".