6621121 has 4 divisors (see below), whose sum is σ = 7130452. Its totient is φ = 6111792.

The previous prime is 6621119. The next prime is 6621127. The reversal of 6621121 is 1211266.

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 2873025 + 3748096 = 1695^2 + 1936^2 .

It is a cyclic number.

It is not a de Polignac number, because 6621121 - 2¹ = 6621119 is a prime.

It is a Duffinian number.

6621121 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (6621127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 254646 + ... + 254671.

It is an arithmetic number, because the mean of its divisors is an integer number (1782613).

Almost surely, 2^6621121 is an apocalyptic number.

It is an amenable number.

6621121 is a deficient number, since it is larger than the sum of its proper divisors (509331).

6621121 is a wasteful number, since it uses less digits than its factorization.

6621121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 509330.

The product of its digits is 144, while the sum is 19.

The square root of 6621121 is about 2573.1539013436. The cubic root of 6621121 is about 187.7776248755. Note that the first 3 decimals are identical.

Adding to 6621121 its reverse (1211266), we get a palindrome (7832387).

The spelling of 6621121 in words is "six million, six hundred twenty-one thousand, one hundred twenty-one".