6651331566 has 128 divisors (see below), whose sum is σ = 16084002816. Its totient is φ = 1810298880.

The previous prime is 6651331543. The next prime is 6651331591.

6651331566 is nontrivially palindromic in base 10.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2198731 + ... + 2201753.

It is an arithmetic number, because the mean of its divisors is an integer number (125656272).

Almost surely, 2^6651331566 is an apocalyptic number.

6651331566 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 6651331566, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8042001408).

6651331566 is an abundant number, since it is smaller than the sum of its proper divisors (9432671250).

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

6651331566 is a wasteful number, since it uses less digits than its factorization.

6651331566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3146.

The product of its digits is 291600, while the sum is 42.

The square root of 6651331566 is about 81555.6960978202. The cubic root of 6651331566 is about 1880.6278616273.

The spelling of 6651331566 in words is "six billion, six hundred fifty-one million, three hundred thirty-one thousand, five hundred sixty-six".