641607968865 has 16 divisors (see below), whose sum is σ = 1050446536128. Its totient is φ = 334232988096.

The previous prime is 641607968831. The next prime is 641607968887. The reversal of 641607968865 is 568869706146.

It is not a de Polignac number, because 641607968865 - 2¹⁶ = 641607903329 is a prime.

It is a super-2 number, since 2×641607968865² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 641607968796 and 641607968805.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 497369874 + ... + 497371163.

It is an arithmetic number, because the mean of its divisors is an integer number (65652908508).

Almost surely, 2^641607968865 is an apocalyptic number.

It is an amenable number.

641607968865 is a deficient number, since it is larger than the sum of its proper divisors (408838567263).

641607968865 is a wasteful number, since it uses less digits than its factorization.

641607968865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 994741088.

The product of its (nonzero) digits is 104509440, while the sum is 66.

The spelling of 641607968865 in words is "six hundred forty-one billion, six hundred seven million, nine hundred sixty-eight thousand, eight hundred sixty-five".