6646717440 has 880 divisors, whose sum is σ = 27392200704. Its totient is φ = 1526169600.

The previous prime is 6646717433. The next prime is 6646717453. The reversal of 6646717440 is 447176466.

It is a tau number, because it is divible by the number of its divisors (880).

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 79 ways as a sum of consecutive naturals, for example, 141419497 + ... + 141419543.

Almost surely, 2^6646717440 is an apocalyptic number.

6646717440 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 6646717440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13696100352).

6646717440 is an abundant number, since it is smaller than the sum of its proper divisors (20745483264).

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

6646717440 is a wasteful number, since it uses less digits than its factorization.

6646717440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126 (or 99 counting only the distinct ones).

The product of its (nonzero) digits is 677376, while the sum is 45.

The square root of 6646717440 is about 81527.4030004636. The cubic root of 6646717440 is about 1880.1928880104.

The spelling of 6646717440 in words is "six billion, six hundred forty-six million, seven hundred seventeen thousand, four hundred forty".