6491516640 has 192 divisors, whose sum is σ = 24744351744. Its totient is φ = 1396482048.

The previous prime is 6491516639. The next prime is 6491516651. The reversal of 6491516640 is 466151946.

It is a super-3 number, since 3×6491516640³ (a number of 30 digits) contains 333 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 6491516592 and 6491516601.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 297 + ... + 113943.

It is an arithmetic number, because the mean of its divisors is an integer number (128876832).

Almost surely, 2^6491516640 is an apocalyptic number.

6491516640 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 6491516640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12372175872).

6491516640 is an abundant number, since it is smaller than the sum of its proper divisors (18252835104).

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

6491516640 is a wasteful number, since it uses less digits than its factorization.

6491516640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113689 (or 113681 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 42.

The square root of 6491516640 is about 80569.9487402096. The cubic root of 6491516640 is about 1865.4433214552.

The spelling of 6491516640 in words is "six billion, four hundred ninety-one million, five hundred sixteen thousand, six hundred forty".