7421220 has 84 divisors (see below), whose sum is σ = 23412060. Its totient is φ = 1975104.

The previous prime is 7421213. The next prime is 7421237. The reversal of 7421220 is 221247.

It can be written as a sum of positive squares in 2 ways, for example, as 4435236 + 2985984 = 2106^2 + 1728^2 .

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 = 7421193 and 7421202.

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 27 ways as a sum of consecutive naturals, for example, 14326 + ... + 14834.

It is an arithmetic number, because the mean of its divisors is an integer number (278715).

Almost surely, 2^7421220 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 7421220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11706030).

7421220 is an abundant number, since it is smaller than the sum of its proper divisors (15990840).

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

7421220 is a wasteful number, since it uses less digits than its factorization.

7421220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 536 (or 519 counting only the distinct ones).

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

The square root of 7421220 is about 2724.1916232160. The cubic root of 7421220 is about 195.0556054440.

Adding to 7421220 its reverse (221247), we get a palindrome (7642467).

The spelling of 7421220 in words is "seven million, four hundred twenty-one thousand, two hundred twenty".