2681864640 has 672 divisors, whose sum is σ = 11804782080. Its totient is φ = 564350976.

The previous prime is 2681864623. The next prime is 2681864641. The reversal of 2681864640 is 464681862.

2681864640 is a `hidden beast` number, since 2 + 6 + 8 + 186 + 464 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2681864641) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 7075971 + ... + 7076349.

It is an arithmetic number, because the mean of its divisors is an integer number (17566640).

Almost surely, 2^2681864640 is an apocalyptic number.

2681864640 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 2681864640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5902391040).

2681864640 is an abundant number, since it is smaller than the sum of its proper divisors (9122917440).

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

2681864640 is a wasteful number, since it uses less digits than its factorization.

2681864640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431 (or 409 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 45.

The square root of 2681864640 is about 51786.7226226955. The cubic root of 2681864640 is about 1389.3519812935.

The spelling of 2681864640 in words is "two billion, six hundred eighty-one million, eight hundred sixty-four thousand, six hundred forty".