640971582841 has 8 divisors (see below), whose sum is σ = 658454574024. Its totient is φ = 623496983040.

The previous prime is 640971582827. The next prime is 640971582871. The reversal of 640971582841 is 148285179046.

It can be written as a sum of positive squares in 4 ways, for example, as 472683750400 + 168287832441 = 687520^2 + 410229^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 640971582841 - 2⁵ = 640971582809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640971582871) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1942840 + ... + 2248681.

It is an arithmetic number, because the mean of its divisors is an integer number (82306821753).

Almost surely, 2^640971582841 is an apocalyptic number.

It is an amenable number.

640971582841 is a deficient number, since it is larger than the sum of its proper divisors (17482991183).

640971582841 is a wasteful number, since it uses less digits than its factorization.

640971582841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4195691.

The product of its (nonzero) digits is 3870720, while the sum is 55.

The spelling of 640971582841 in words is "six hundred forty billion, nine hundred seventy-one million, five hundred eighty-two thousand, eight hundred forty-one".