4221520 has 20 divisors (see below), whose sum is σ = 9815220. Its totient is φ = 1688576.

The previous prime is 4221499. The next prime is 4221521. The reversal of 4221520 is 251224.

It can be written as a sum of positive squares in 2 ways, for example, as 1317904 + 2903616 = 1148^2 + 1704^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×4221520² = 35642462220800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a junction number, because it is equal to n+sod(n) for n = 4221494 and 4221503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4221521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26305 + ... + 26464.

It is an arithmetic number, because the mean of its divisors is an integer number (490761).

Almost surely, 2^4221520 is an apocalyptic number.

4221520 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

4221520 is an abundant number, since it is smaller than the sum of its proper divisors (5593700).

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

4221520 is a wasteful number, since it uses less digits than its factorization.

4221520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52782 (or 52776 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 4221520 is about 2054.6337873207. The cubic root of 4221520 is about 161.6179586616.

Adding to 4221520 its reverse (251224), we get a palindrome (4472744).

It can be divided in two parts, 42 and 21520, that multiplied together give a triangular number (903840 = T₁₃₄₄).

The spelling of 4221520 in words is "four million, two hundred twenty-one thousand, five hundred twenty".