2708657640 has 216 divisors, whose sum is σ = 9577782630. Its totient is φ = 663586560.

The previous prime is 2708657621. The next prime is 2708657647. The reversal of 2708657640 is 467568072.

2708657640 is a `hidden beast` number, since 2 + 70 + 8 + 6 + 576 + 4 + 0 = 666.

2708657640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 1168409124 + 1540248516 = 34182^2 + 39246^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (2708657647) by changing a digit.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 12837135 + ... + 12837345.

Almost surely, 2^2708657640 is an apocalyptic number.

2708657640 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 2708657640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4788891315).

2708657640 is an abundant number, since it is smaller than the sum of its proper divisors (6869124990).

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

2708657640 is a wasteful number, since it uses less digits than its factorization.

2708657640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 465 (or 234 counting only the distinct ones).

The product of its (nonzero) digits is 564480, while the sum is 45.

The square root of 2708657640 is about 52044.7657310512. The cubic root of 2708657640 is about 1393.9634030382.

The spelling of 2708657640 in words is "two billion, seven hundred eight million, six hundred fifty-seven thousand, six hundred forty".