6659400660 has 96 divisors (see below), whose sum is σ = 20543048064. Its totient is φ = 1598400000.

The previous prime is 6659400653. The next prime is 6659400661. The reversal of 6659400660 is 660049566.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6659400661) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16710 + ... + 116610.

It is an arithmetic number, because the mean of its divisors is an integer number (213990084).

Almost surely, 2^6659400660 is an apocalyptic number.

6659400660 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6659400660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10271524032).

6659400660 is an abundant number, since it is smaller than the sum of its proper divisors (13883647404).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6659400660 is a wasteful number, since it uses less digits than its factorization.

6659400660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100025 (or 100023 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 42.

The square root of 6659400660 is about 81605.1509403665. The cubic root of 6659400660 is about 1881.3880517963.

The spelling of 6659400660 in words is "six billion, six hundred fifty-nine million, four hundred thousand, six hundred sixty".