7263721 has 4 divisors (see below), whose sum is σ = 7269444. Its totient is φ = 7258000.

The previous prime is 7263679. The next prime is 7263727. The reversal of 7263721 is 1273627.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1273627 = 19 ⋅67033.

It can be written as a sum of positive squares in 2 ways, for example, as 3515625 + 3748096 = 1875^2 + 1936^2 .

It is a cyclic number.

It is not a de Polignac number, because 7263721 - 2⁷ = 7263593 is a prime.

It is a Duffinian number.

7263721 is a lucky number.

It is a nialpdrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 7263721.

It is not an unprimeable number, because it can be changed into a prime (7263727) 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, 10 + ... + 3811.

It is an arithmetic number, because the mean of its divisors is an integer number (1817361).

Almost surely, 2^7263721 is an apocalyptic number.

It is an amenable number.

7263721 is a deficient number, since it is larger than the sum of its proper divisors (5723).

7263721 is a wasteful number, since it uses less digits than its factorization.

7263721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5722.

The product of its digits is 3528, while the sum is 28.

The square root of 7263721 is about 2695.1291249215. The cubic root of 7263721 is about 193.6658523248.

The spelling of 7263721 in words is "seven million, two hundred sixty-three thousand, seven hundred twenty-one".