7217428 has 12 divisors (see below), whose sum is σ = 12697300. Its totient is φ = 3589632.

The previous prime is 7217417. The next prime is 7217429. The reversal of 7217428 is 8247127.

It can be written as a sum of positive squares in 2 ways, for example, as 4112784 + 3104644 = 2028^2 + 1762^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 7217428.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7217429) 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, 3903 + ... + 5446.

Almost surely, 2^7217428 is an apocalyptic number.

It is an amenable number.

7217428 is a deficient number, since it is larger than the sum of its proper divisors (5479872).

7217428 is a wasteful number, since it uses less digits than its factorization.

7217428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9546 (or 9544 counting only the distinct ones).

The product of its digits is 6272, while the sum is 31.

The square root of 7217428 is about 2686.5271262357. The cubic root of 7217428 is about 193.2535527609.

The spelling of 7217428 in words is "seven million, two hundred seventeen thousand, four hundred twenty-eight".