7221420 has 96 divisors (see below), whose sum is σ = 23063040. Its totient is φ = 1874880.

The previous prime is 7221391. The next prime is 7221439. The reversal of 7221420 is 241227.

7221420 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 7221393 and 7221402.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 23065 + ... + 23375.

It is an arithmetic number, because the mean of its divisors is an integer number (240240).

Almost surely, 2^7221420 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 7221420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11531520).

7221420 is an abundant number, since it is smaller than the sum of its proper divisors (15841620).

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

7221420 is a wasteful number, since it uses less digits than its factorization.

7221420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 372 (or 364 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 18.

The square root of 7221420 is about 2687.2699901573. The cubic root of 7221420 is about 193.2891760693.

Adding to 7221420 its reverse (241227), we get a palindrome (7462647).

The spelling of 7221420 in words is "seven million, two hundred twenty-one thousand, four hundred twenty".