7221685 has 8 divisors (see below), whose sum is σ = 9175896. Its totient is φ = 5437440.

The previous prime is 7221661. The next prime is 7221689. The reversal of 7221685 is 5861227.

It can be written as a sum of positive squares in 4 ways, for example, as 2172676 + 5049009 = 1474^2 + 2247^2 .

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

It is not a de Polignac number, because 7221685 - 2⁹ = 7221173 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 (7221689) 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 7 ways as a sum of consecutive naturals, for example, 42396 + ... + 42565.

It is an arithmetic number, because the mean of its divisors is an integer number (1146987).

Almost surely, 2^7221685 is an apocalyptic number.

It is an amenable number.

7221685 is a deficient number, since it is larger than the sum of its proper divisors (1954211).

7221685 is a wasteful number, since it uses less digits than its factorization.

7221685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84983.

The product of its digits is 6720, while the sum is 31.

The square root of 7221685 is about 2687.3192962504. The cubic root of 7221685 is about 193.2915403783.

The spelling of 7221685 in words is "seven million, two hundred twenty-one thousand, six hundred eighty-five".