6440211640 has 32 divisors (see below), whose sum is σ = 14728030560. Its totient is φ = 2533852800.

The previous prime is 6440211581. The next prime is 6440211641. The reversal of 6440211640 is 461120446.

6440211640 is a modest number, since divided by 211640 gives 6440 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 6440211599 and 6440211608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6440211641) 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, 1317276 + ... + 1322155.

It is an arithmetic number, because the mean of its divisors is an integer number (460250955).

Almost surely, 2^6440211640 is an apocalyptic number.

It is an amenable number.

6440211640 is an abundant number, since it is smaller than the sum of its proper divisors (8287818920).

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

6440211640 is a wasteful number, since it uses less digits than its factorization.

6440211640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2639503 (or 2639499 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 6440211640 is about 80250.9292158041. The cubic root of 6440211640 is about 1860.5158741742.

The spelling of 6440211640 in words is "six billion, four hundred forty million, two hundred eleven thousand, six hundred forty".