6440853739 has 4 divisors (see below), whose sum is σ = 6443694640. Its totient is φ = 6438012840.

The previous prime is 6440853697. The next prime is 6440853743. The reversal of 6440853739 is 9373580446.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9373580446 = 2 ⋅4686790223.

It is a cyclic number.

It is not a de Polignac number, because 6440853739 - 2⁷ = 6440853611 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6440853692 and 6440853701.

It is not an unprimeable number, because it can be changed into a prime (6420853739) 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, 1417047 + ... + 1421584.

It is an arithmetic number, because the mean of its divisors is an integer number (1610923660).

Almost surely, 2^6440853739 is an apocalyptic number.

6440853739 is a deficient number, since it is larger than the sum of its proper divisors (2840901).

6440853739 is a wasteful number, since it uses less digits than its factorization.

6440853739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2840900.

The product of its (nonzero) digits is 2177280, while the sum is 49.

The square root of 6440853739 is about 80254.9296865931. The cubic root of 6440853739 is about 1860.5777042169.

The spelling of 6440853739 in words is "six billion, four hundred forty million, eight hundred fifty-three thousand, seven hundred thirty-nine".