2640435840 has 512 divisors, whose sum is σ = 10857369600. Its totient is φ = 593989632.

The previous prime is 2640435839. The next prime is 2640435887. The reversal of 2640435840 is 485340462.

2640435840 is a `hidden beast` number, since 2 + 640 + 4 + 3 + 5 + 8 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 2640435795 and 2640435804.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 10039549 + ... + 10039811.

It is an arithmetic number, because the mean of its divisors is an integer number (21205800).

Almost surely, 2^2640435840 is an apocalyptic number.

2640435840 is a gapful number since it is divisible by the number (20) 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 2640435840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5428684800).

2640435840 is an abundant number, since it is smaller than the sum of its proper divisors (8216933760).

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

2640435840 is a wasteful number, since it uses less digits than its factorization.

2640435840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 381 (or 363 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 36.

The square root of 2640435840 is about 51385.1714018743. The cubic root of 2640435840 is about 1382.1606983541.

The spelling of 2640435840 in words is "two billion, six hundred forty million, four hundred thirty-five thousand, eight hundred forty".