439645021 has 4 divisors (see below), whose sum is σ = 443998044. Its totient is φ = 435292000.

The previous prime is 439644991. The next prime is 439645027. The reversal of 439645021 is 120546934.

It is a happy number.

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 214944921 + 224700100 = 14661^2 + 14990^2 .

It is a cyclic number.

It is not a de Polignac number, because 439645021 - 2⁷ = 439644893 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 (439645027) 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, 2176360 + ... + 2176561.

It is an arithmetic number, because the mean of its divisors is an integer number (110999511).

Almost surely, 2^439645021 is an apocalyptic number.

It is an amenable number.

439645021 is a deficient number, since it is larger than the sum of its proper divisors (4353023).

439645021 is a wasteful number, since it uses less digits than its factorization.

439645021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4353022.

The product of its (nonzero) digits is 25920, while the sum is 34.

The square root of 439645021 is about 20967.7137761846. The cubic root of 439645021 is about 760.3858964761.

The spelling of 439645021 in words is "four hundred thirty-nine million, six hundred forty-five thousand, twenty-one".