4520721 has 4 divisors (see below), whose sum is σ = 6027632. Its totient is φ = 3013812.

The previous prime is 4520713. The next prime is 4520729. The reversal of 4520721 is 1270254.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (4520713) and next prime (4520729).

It is not a de Polignac number, because 4520721 - 2³ = 4520713 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (4520729) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 753451 + ... + 753456.

It is an arithmetic number, because the mean of its divisors is an integer number (1506908).

Almost surely, 2^4520721 is an apocalyptic number.

It is an amenable number.

4520721 is a deficient number, since it is larger than the sum of its proper divisors (1506911).

4520721 is a wasteful number, since it uses less digits than its factorization.

4520721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1506910.

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 4520721 is about 2126.1987207220. The cubic root of 4520721 is about 165.3493790611.

Adding to 4520721 its reverse (1270254), we get a palindrome (5790975).

The spelling of 4520721 in words is "four million, five hundred twenty thousand, seven hundred twenty-one".