6699321720 has 768 divisors, whose sum is σ = 28933632000. Its totient is φ = 1304875008.

The previous prime is 6699321709. The next prime is 6699321749. The reversal of 6699321720 is 271239966.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 29254566 + ... + 29254794.

It is an arithmetic number, because the mean of its divisors is an integer number (37674000).

Almost surely, 2^6699321720 is an apocalyptic number.

6699321720 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 6699321720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14466816000).

6699321720 is an abundant number, since it is smaller than the sum of its proper divisors (22234310280).

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

6699321720 is a wasteful number, since it uses less digits than its factorization.

6699321720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332 (or 325 counting only the distinct ones).

The product of its (nonzero) digits is 244944, while the sum is 45.

The square root of 6699321720 is about 81849.3843593218. The cubic root of 6699321720 is about 1885.1400121617.

The spelling of 6699321720 in words is "six billion, six hundred ninety-nine million, three hundred twenty-one thousand, seven hundred twenty".