6668726820 has 384 divisors, whose sum is σ = 23011000320. Its totient is φ = 1410877440.

The previous prime is 6668726809. The next prime is 6668726849. The reversal of 6668726820 is 286278666.

It is a happy number.

It is a hoax number, since the sum of its digits (51) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 52509597 + ... + 52509723.

It is an arithmetic number, because the mean of its divisors is an integer number (59924480).

Almost surely, 2^6668726820 is an apocalyptic number.

6668726820 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 6668726820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11505500160).

6668726820 is an abundant number, since it is smaller than the sum of its proper divisors (16342273500).

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

6668726820 is a wasteful number, since it uses less digits than its factorization.

6668726820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323 (or 321 counting only the distinct ones).

The product of its (nonzero) digits is 2322432, while the sum is 51.

The square root of 6668726820 is about 81662.2729294256. The cubic root of 6668726820 is about 1882.2659056468.

The spelling of 6668726820 in words is "six billion, six hundred sixty-eight million, seven hundred twenty-six thousand, eight hundred twenty".