6685520389 has 12 divisors (see below), whose sum is σ = 6794870220. Its totient is φ = 6577894400.

The previous prime is 6685520381. The next prime is 6685520399. The reversal of 6685520389 is 9830255866.

It can be written as a sum of positive squares in 2 ways, for example, as 3642122500 + 3043397889 = 60350^2 + 55167^2 .

It is not a de Polignac number, because 6685520389 - 2³ = 6685520381 is a prime.

It is a super-2 number, since 2×6685520389² = 89392365743469422642, 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 (6685520381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3230247 + ... + 3232315.

It is an arithmetic number, because the mean of its divisors is an integer number (566239185).

Almost surely, 2^6685520389 is an apocalyptic number.

It is an amenable number.

6685520389 is a deficient number, since it is larger than the sum of its proper divisors (109349831).

6685520389 is an equidigital number, since it uses as much as digits as its factorization.

6685520389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2852 (or 2781 counting only the distinct ones).

The product of its (nonzero) digits is 3110400, while the sum is 52.

The square root of 6685520389 is about 81765.0315782976. The cubic root of 6685520389 is about 1883.8445910676.

The spelling of 6685520389 in words is "six billion, six hundred eighty-five million, five hundred twenty thousand, three hundred eighty-nine".