6659917920 has 144 divisors (see below), whose sum is σ = 23066512560. Its totient is φ = 1749445632.

The previous prime is 6659917883. The next prime is 6659918021. The reversal of 6659917920 is 297199566.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×6659917920² = 88709013402274252800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 61966 + ... + 130994.

It is an arithmetic number, because the mean of its divisors is an integer number (160184115).

Almost surely, 2^6659917920 is an apocalyptic number.

6659917920 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 6659917920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11533256280).

6659917920 is an abundant number, since it is smaller than the sum of its proper divisors (16406594640).

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

6659917920 is a wasteful number, since it uses less digits than its factorization.

6659917920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69117 (or 69106 counting only the distinct ones).

The product of its (nonzero) digits is 1837080, while the sum is 54.

The square root of 6659917920 is about 81608.3201640617. The cubic root of 6659917920 is about 1881.4367619650.

The spelling of 6659917920 in words is "six billion, six hundred fifty-nine million, nine hundred seventeen thousand, nine hundred twenty".