642005187265 has 16 divisors (see below), whose sum is σ = 831048772176. Its totient is φ = 473307264000.

The previous prime is 642005187259. The next prime is 642005187287. The reversal of 642005187265 is 562781500246.

It can be written as a sum of positive squares in 8 ways, for example, as 14425931664 + 627579255601 = 120108^2 + 792199^2 .

It is not a de Polignac number, because 642005187265 - 2⁷ = 642005187137 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8178076 + ... + 8256205.

It is an arithmetic number, because the mean of its divisors is an integer number (51940548261).

Almost surely, 2^642005187265 is an apocalyptic number.

642005187265 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

642005187265 is a deficient number, since it is larger than the sum of its proper divisors (189043584911).

642005187265 is a wasteful number, since it uses less digits than its factorization.

642005187265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16434900.

The product of its (nonzero) digits is 806400, while the sum is 46.

The spelling of 642005187265 in words is "six hundred forty-two billion, five million, one hundred eighty-seven thousand, two hundred sixty-five".