6221621 has 8 divisors (see below), whose sum is σ = 7137984. Its totient is φ = 5312160.

The previous prime is 6221591. The next prime is 6221629. The reversal of 6221621 is 1261226.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 6221621 - 2⁶ = 6221557 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 6221593 and 6221602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6221629) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 386 + ... + 3548.

It is an arithmetic number, because the mean of its divisors is an integer number (892248).

Almost surely, 2^6221621 is an apocalyptic number.

It is an amenable number.

6221621 is a deficient number, since it is larger than the sum of its proper divisors (916363).

6221621 is a wasteful number, since it uses less digits than its factorization.

6221621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3451.

The product of its digits is 288, while the sum is 20.

The square root of 6221621 is about 2494.3177423897. The cubic root of 6221621 is about 183.9223542113.

Adding to 6221621 its reverse (1261226), we get a palindrome (7482847).

It can be divided in two parts, 62216 and 21, that multiplied together give a triangular number (1306536 = T₁₆₁₆).

The spelling of 6221621 in words is "six million, two hundred twenty-one thousand, six hundred twenty-one".