5643721 has 4 divisors (see below), whose sum is σ = 5796292. Its totient is φ = 5491152.

The previous prime is 5643709. The next prime is 5643727. The reversal of 5643721 is 1273465.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4665600 + 978121 = 2160^2 + 989^2 .

It is a cyclic number.

It is not a de Polignac number, because 5643721 - 2⁷ = 5643593 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 5643721.

It is not an unprimeable number, because it can be changed into a prime (5643727) 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, 76230 + ... + 76303.

It is an arithmetic number, because the mean of its divisors is an integer number (1449073).

Almost surely, 2^5643721 is an apocalyptic number.

It is an amenable number.

5643721 is a deficient number, since it is larger than the sum of its proper divisors (152571).

5643721 is a wasteful number, since it uses less digits than its factorization.

5643721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152570.

The product of its digits is 5040, while the sum is 28.

The square root of 5643721 is about 2375.6517000604. The cubic root of 5643721 is about 178.0417462999.

The spelling of 5643721 in words is "five million, six hundred forty-three thousand, seven hundred twenty-one".