7200721 has 4 divisors (see below), whose sum is σ = 7855344. Its totient is φ = 6546100.

The previous prime is 7200719. The next prime is 7200733. The reversal of 7200721 is 1270027.

It is the 1096-th star number.

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 not a de Polignac number, because 7200721 - 2¹ = 7200719 is a prime.

It is a Duffinian number.

7200721 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (7200701) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 327295 + ... + 327316.

It is an arithmetic number, because the mean of its divisors is an integer number (1963836).

Almost surely, 2^7200721 is an apocalyptic number.

It is an amenable number.

7200721 is a deficient number, since it is larger than the sum of its proper divisors (654623).

7200721 is a wasteful number, since it uses less digits than its factorization.

7200721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 654622.

The product of its (nonzero) digits is 196, while the sum is 19.

The square root of 7200721 is about 2683.4159200541. The cubic root of 7200721 is about 193.1043222416.

Adding to 7200721 its reverse (1270027), we get a palindrome (8470748).

It can be divided in two parts, 7200 and 721, that added together give a square (7921 = 89²).

The spelling of 7200721 in words is "seven million, two hundred thousand, seven hundred twenty-one".