6440715687 has 8 divisors (see below), whose sum is σ = 9814423936. Its totient is φ = 3680408952.

The previous prime is 6440715653. The next prime is 6440715751. The reversal of 6440715687 is 7865170446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 6440715687 - 2⁶ = 6440715623 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6440715607) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 153350353 + ... + 153350394.

It is an arithmetic number, because the mean of its divisors is an integer number (1226802992).

Almost surely, 2^6440715687 is an apocalyptic number.

6440715687 is a deficient number, since it is larger than the sum of its proper divisors (3373708249).

6440715687 is a wasteful number, since it uses less digits than its factorization.

6440715687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306700757.

The product of its (nonzero) digits is 1128960, while the sum is 48.

The square root of 6440715687 is about 80254.0695977469. The cubic root of 6440715687 is about 1860.5644110356.

The spelling of 6440715687 in words is "six billion, four hundred forty million, seven hundred fifteen thousand, six hundred eighty-seven".