2005653640 has 16 divisors (see below), whose sum is σ = 4512720780. Its totient is φ = 802261440.

The previous prime is 2005653631. The next prime is 2005653673. The reversal of 2005653640 is 463565002.

It can be written as a sum of positive squares in 2 ways, for example, as 1920017124 + 85636516 = 43818^2 + 9254^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25070631 + ... + 25070710.

Almost surely, 2^2005653640 is an apocalyptic number.

2005653640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2005653640 is an abundant number, since it is smaller than the sum of its proper divisors (2507067140).

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

2005653640 is a wasteful number, since it uses less digits than its factorization.

2005653640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50141352 (or 50141348 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 31.

The square root of 2005653640 is about 44784.5245592716. The cubic root of 2005653640 is about 1261.1071229983.

The spelling of 2005653640 in words is "two billion, five million, six hundred fifty-three thousand, six hundred forty".