6471221 has 4 divisors (see below), whose sum is σ = 6530700. Its totient is φ = 6411744.

The previous prime is 6471193. The next prime is 6471233. The reversal of 6471221 is 1221746.

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 2002225 + 4468996 = 1415^2 + 2114^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6471221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6471251) 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 3 ways as a sum of consecutive naturals, for example, 29576 + ... + 29793.

It is an arithmetic number, because the mean of its divisors is an integer number (1632675).

Almost surely, 2^6471221 is an apocalyptic number.

It is an amenable number.

6471221 is a deficient number, since it is larger than the sum of its proper divisors (59479).

6471221 is a wasteful number, since it uses less digits than its factorization.

6471221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59478.

The product of its digits is 672, while the sum is 23.

The square root of 6471221 is about 2543.8594693890. The cubic root of 6471221 is about 186.3497197331.

Adding to 6471221 its reverse (1221746), we get a palindrome (7692967).

It can be divided in two parts, 647 and 1221, that multiplied together give a palindrome (789987).

The spelling of 6471221 in words is "six million, four hundred seventy-one thousand, two hundred twenty-one".