7221424 has 60 divisors (see below), whose sum is σ = 16652208. Its totient is φ = 3024000.

The previous prime is 7221391. The next prime is 7221439. The reversal of 7221424 is 4241227.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 7221395 and 7221404.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 47749 + ... + 47899.

Almost surely, 2^7221424 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7221424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8326104).

7221424 is an abundant number, since it is smaller than the sum of its proper divisors (9430784).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7221424 is a wasteful number, since it uses less digits than its factorization.

7221424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234 (or 221 counting only the distinct ones).

The product of its digits is 896, while the sum is 22.

The square root of 7221424 is about 2687.2707344069. The cubic root of 7221424 is about 193.2892117574.

The spelling of 7221424 in words is "seven million, two hundred twenty-one thousand, four hundred twenty-four".