6640573381 has 8 divisors (see below), whose sum is σ = 7397986680. Its totient is φ = 5918388672.

The previous prime is 6640573327. The next prime is 6640573403. The reversal of 6640573381 is 1833750466.

It can be written as a sum of positive squares in 4 ways, for example, as 29257281 + 6611316100 = 5409^2 + 81310^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 6640573381 - 2²⁵ = 6607018949 is a prime.

It is a super-2 number, since 2×6640573381² = 88194429656891542322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6640523381) 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 7 ways as a sum of consecutive naturals, for example, 8806750 + ... + 8807503.

It is an arithmetic number, because the mean of its divisors is an integer number (924748335).

Almost surely, 2^6640573381 is an apocalyptic number.

It is an amenable number.

6640573381 is a deficient number, since it is larger than the sum of its proper divisors (757413299).

6640573381 is a wasteful number, since it uses less digits than its factorization.

6640573381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17614295.

The product of its (nonzero) digits is 362880, while the sum is 43.

The square root of 6640573381 is about 81489.7133446915. The cubic root of 6640573381 is about 1879.6133750186.

The spelling of 6640573381 in words is "six billion, six hundred forty million, five hundred seventy-three thousand, three hundred eighty-one".