6857521969 has 4 divisors (see below), whose sum is σ = 6882278644. Its totient is φ = 6832765296.

The previous prime is 6857521927. The next prime is 6857522011. The reversal of 6857521969 is 9691257586.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9691257586 = 2 ⋅4845628793.

It is an interprime number because it is at equal distance from previous prime (6857521927) and next prime (6857522011).

It can be written as a sum of positive squares in 2 ways, for example, as 582981025 + 6274540944 = 24145^2 + 79212^2 .

It is a cyclic number.

It is not a de Polignac number, because 6857521969 - 2¹³ = 6857513777 is a prime.

It is a super-2 number, since 2×6857521969² = 94051215110635273922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6857521169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12377922 + ... + 12378475.

It is an arithmetic number, because the mean of its divisors is an integer number (1720569661).

Almost surely, 2^6857521969 is an apocalyptic number.

It is an amenable number.

6857521969 is a deficient number, since it is larger than the sum of its proper divisors (24756675).

6857521969 is a wasteful number, since it uses less digits than its factorization.

6857521969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24756674.

The product of its digits is 8164800, while the sum is 58.

The square root of 6857521969 is about 82810.1561947567. The cubic root of 6857521969 is about 1899.8635145726.

The spelling of 6857521969 in words is "six billion, eight hundred fifty-seven million, five hundred twenty-one thousand, nine hundred sixty-nine".