1640352005 has 4 divisors (see below), whose sum is σ = 1968422412. Its totient is φ = 1312281600.

The previous prime is 1640351963. The next prime is 1640352013. The reversal of 1640352005 is 5002530461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5002530461 = 2129 ⋅2349709.

It can be written as a sum of positive squares in 2 ways, for example, as 446096641 + 1194255364 = 21121^2 + 34558^2 .

It is not a de Polignac number, because 1640352005 - 2¹⁴ = 1640335621 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 164035196 + ... + 164035205.

It is an arithmetic number, because the mean of its divisors is an integer number (492105603).

Almost surely, 2^1640352005 is an apocalyptic number.

It is an amenable number.

1640352005 is a deficient number, since it is larger than the sum of its proper divisors (328070407).

1640352005 is an equidigital number, since it uses as much as digits as its factorization.

1640352005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328070406.

The product of its (nonzero) digits is 3600, while the sum is 26.

The square root of 1640352005 is about 40501.2593014094. The cubic root of 1640352005 is about 1179.3580739587.

Adding to 1640352005 its reverse (5002530461), we get a palindrome (6642882466).

The spelling of 1640352005 in words is "one billion, six hundred forty million, three hundred fifty-two thousand, five".