6857539649 has 4 divisors (see below), whose sum is σ = 6858723540. Its totient is φ = 6856355760.

The previous prime is 6857539573. The next prime is 6857539669. The reversal of 6857539649 is 9469357586.

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 4347028624 + 2510511025 = 65932^2 + 50105^2 .

It is a cyclic number.

It is not a de Polignac number, because 6857539649 - 2⁸ = 6857539393 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6857539591 and 6857539600.

It is not an unprimeable number, because it can be changed into a prime (6857539669) 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, 583214 + ... + 594855.

It is an arithmetic number, because the mean of its divisors is an integer number (1714680885).

Almost surely, 2^6857539649 is an apocalyptic number.

It is an amenable number.

6857539649 is a deficient number, since it is larger than the sum of its proper divisors (1183891).

6857539649 is a wasteful number, since it uses less digits than its factorization.

6857539649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1183890.

The product of its digits is 48988800, while the sum is 62.

The square root of 6857539649 is about 82810.2629448790. The cubic root of 6857539649 is about 1899.8651473081.

The spelling of 6857539649 in words is "six billion, eight hundred fifty-seven million, five hundred thirty-nine thousand, six hundred forty-nine".