1445644021 has 4 divisors (see below), whose sum is σ = 1445824972. Its totient is φ = 1445463072.

The previous prime is 1445644009. The next prime is 1445644033. The reversal of 1445644021 is 1204465441.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1204465441 = 139 ⋅8665219.

It is an interprime number because it is at equal distance from previous prime (1445644009) and next prime (1445644033).

It can be written as a sum of positive squares in 2 ways, for example, as 298805796 + 1146838225 = 17286^2 + 33865^2 .

It is a cyclic number.

It is not a de Polignac number, because 1445644021 - 2¹¹ = 1445641973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1445644061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 77910 + ... + 94663.

It is an arithmetic number, because the mean of its divisors is an integer number (361456243).

Almost surely, 2^1445644021 is an apocalyptic number.

It is an amenable number.

1445644021 is a deficient number, since it is larger than the sum of its proper divisors (180951).

1445644021 is an equidigital number, since it uses as much as digits as its factorization.

1445644021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180950.

The product of its (nonzero) digits is 15360, while the sum is 31.

The square root of 1445644021 is about 38021.6257016977. The cubic root of 1445644021 is about 1130.7166521943.

The spelling of 1445644021 in words is "one billion, four hundred forty-five million, six hundred forty-four thousand, twenty-one".