1445821 has 4 divisors (see below), whose sum is σ = 1557052. Its totient is φ = 1334592.

The previous prime is 1445797. The next prime is 1445827. The reversal of 1445821 is 1285441.

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 662596 + 783225 = 814^2 + 885^2 .

It is a cyclic number.

It is not a de Polignac number, because 1445821 - 2¹³ = 1437629 is a prime.

It is a Duffinian number.

1445821 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1445827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55596 + ... + 55621.

It is an arithmetic number, because the mean of its divisors is an integer number (389263).

2^1445821 is an apocalyptic number.

It is an amenable number.

1445821 is a deficient number, since it is larger than the sum of its proper divisors (111231).

1445821 is a wasteful number, since it uses less digits than its factorization.

1445821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111230.

The product of its digits is 1280, while the sum is 25.

The square root of 1445821 is about 1202.4229705058. The cubic root of 1445821 is about 113.0762791939.

The spelling of 1445821 in words is "one million, four hundred forty-five thousand, eight hundred twenty-one".