6491330664 has 192 divisors, whose sum is σ = 21215053440. Its totient is φ = 1637475840.

The previous prime is 6491330663. The next prime is 6491330707. The reversal of 6491330664 is 4660331946.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (6491330663) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 342394 + ... + 360854.

It is an arithmetic number, because the mean of its divisors is an integer number (110495070).

Almost surely, 2^6491330664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6491330664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10607526720).

6491330664 is an abundant number, since it is smaller than the sum of its proper divisors (14723722776).

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

6491330664 is a wasteful number, since it uses less digits than its factorization.

6491330664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18520 (or 18509 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 42.

The square root of 6491330664 is about 80568.7946043628. The cubic root of 6491330664 is about 1865.4255068715.

The spelling of 6491330664 in words is "six billion, four hundred ninety-one million, three hundred thirty thousand, six hundred sixty-four".