8440634640 has 160 divisors (see below), whose sum is σ = 27980816256. Its totient is φ = 2097356800.

The previous prime is 8440634611. The next prime is 8440634663. The reversal of 8440634640 is 464360448.

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, 401839 + ... + 422321.

Almost surely, 2^8440634640 is an apocalyptic number.

8440634640 is a gapful number since it is divisible by the number (80) 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 8440634640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13990408128).

8440634640 is an abundant number, since it is smaller than the sum of its proper divisors (19540181616).

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

8440634640 is a wasteful number, since it uses less digits than its factorization.

8440634640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20617 (or 20611 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 39.

The square root of 8440634640 is about 91872.9265888488. The cubic root of 8440634640 is about 2036.0652915145.

The spelling of 8440634640 in words is "eight billion, four hundred forty million, six hundred thirty-four thousand, six hundred forty".