1443721 has 4 divisors (see below), whose sum is σ = 1463572. Its totient is φ = 1423872.

The previous prime is 1443719. The next prime is 1443727. The reversal of 1443721 is 1273441.

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 746496 + 697225 = 864^2 + 835^2 .

It is a cyclic number.

It is not a de Polignac number, because 1443721 - 2¹ = 1443719 is a prime.

It is a Duffinian number.

1443721 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 1443692 and 1443701.

It is not an unprimeable number, because it can be changed into a prime (1443727) 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, 9816 + ... + 9961.

It is an arithmetic number, because the mean of its divisors is an integer number (365893).

2^1443721 is an apocalyptic number.

It is an amenable number.

1443721 is a deficient number, since it is larger than the sum of its proper divisors (19851).

1443721 is an equidigital number, since it uses as much as digits as its factorization.

1443721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19850.

The product of its digits is 672, while the sum is 22.

The square root of 1443721 is about 1201.5494163787. The cubic root of 1443721 is about 113.0215063355.

It can be divided in two parts, 1443 and 721, that multiplied together give a triangular number (1040403 = T₁₄₄₂).

The spelling of 1443721 in words is "one million, four hundred forty-three thousand, seven hundred twenty-one".