646440101999 has 8 divisors (see below), whose sum is σ = 664524964512. Its totient is φ = 628604686080.

The previous prime is 646440101911. The next prime is 646440102023. The reversal of 646440101999 is 999101044646.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646440101999 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 646440101999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646440101599) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62356394 + ... + 62366759.

It is an arithmetic number, because the mean of its divisors is an integer number (83065620564).

Almost surely, 2^646440101999 is an apocalyptic number.

646440101999 is a deficient number, since it is larger than the sum of its proper divisors (18084862513).

646440101999 is a wasteful number, since it uses less digits than its factorization.

646440101999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124723297.

The product of its (nonzero) digits is 1679616, while the sum is 53.

The spelling of 646440101999 in words is "six hundred forty-six billion, four hundred forty million, one hundred one thousand, nine hundred ninety-nine".