6515740644 has 48 divisors (see below), whose sum is σ = 17385062016. Its totient is φ = 1860595200.

The previous prime is 6515740643. The next prime is 6515740657. The reversal of 6515740644 is 4460475156.

It is a super-2 number, since 2×6515740644² = 84909752279747069472, which contains 22 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 = 6515740596 and 6515740605.

It is not an unprimeable number, because it can be changed into a prime (6515740643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 135484 + ... + 177164.

It is an arithmetic number, because the mean of its divisors is an integer number (362188792).

Almost surely, 2^6515740644 is an apocalyptic number.

It is an amenable number.

6515740644 is an abundant number, since it is smaller than the sum of its proper divisors (10869321372).

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

6515740644 is a wasteful number, since it uses less digits than its factorization.

6515740644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43556 (or 43554 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 42.

The square root of 6515740644 is about 80720.1377848180. The cubic root of 6515740644 is about 1867.7608288597.

The spelling of 6515740644 in words is "six billion, five hundred fifteen million, seven hundred forty thousand, six hundred forty-four".