4340440021 has 4 divisors (see below), whose sum is σ = 4389209100. Its totient is φ = 4291670944.

The previous prime is 4340440003. The next prime is 4340440033. The reversal of 4340440021 is 1200440434.

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 2723274225 + 1617165796 = 52185^2 + 40214^2 .

It is a cyclic number.

It is not a de Polignac number, because 4340440021 - 2⁷ = 4340439893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 4340439974 and 4340440001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4340440061) 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, 24384406 + ... + 24384583.

It is an arithmetic number, because the mean of its divisors is an integer number (1097302275).

Almost surely, 2^4340440021 is an apocalyptic number.

It is an amenable number.

4340440021 is a deficient number, since it is larger than the sum of its proper divisors (48769079).

4340440021 is an equidigital number, since it uses as much as digits as its factorization.

4340440021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48769078.

The product of its (nonzero) digits is 1536, while the sum is 22.

The square root of 4340440021 is about 65882.0159148155. The cubic root of 4340440021 is about 1631.2151753775.

Adding to 4340440021 its reverse (1200440434), we get a palindrome (5540880455).

The spelling of 4340440021 in words is "four billion, three hundred forty million, four hundred forty thousand, twenty-one".