646020455665 has 8 divisors (see below), whose sum is σ = 834857204328. Its totient is φ = 477061259520.

The previous prime is 646020455611. The next prime is 646020455681. The reversal of 646020455665 is 566554020646.

It can be written as a sum of positive squares in 4 ways, for example, as 83124385969 + 562896069696 = 288313^2 + 750264^2 .

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

It is not a de Polignac number, because 646020455665 - 2⁷ = 646020455537 is a prime.

It is a super-2 number, since 2×646020455665² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4969388056 + ... + 4969388185.

It is an arithmetic number, because the mean of its divisors is an integer number (104357150541).

Almost surely, 2^646020455665 is an apocalyptic number.

646020455665 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

646020455665 is a deficient number, since it is larger than the sum of its proper divisors (188836748663).

646020455665 is a wasteful number, since it uses less digits than its factorization.

646020455665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9938776259.

The product of its (nonzero) digits is 5184000, while the sum is 49.

The spelling of 646020455665 in words is "six hundred forty-six billion, twenty million, four hundred fifty-five thousand, six hundred sixty-five".