646579634219 has 4 divisors (see below), whose sum is σ = 646584412344. Its totient is φ = 646574856096.

The previous prime is 646579634177. The next prime is 646579634237. The reversal of 646579634219 is 912436975646.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646579634219 is a prime.

It is a super-2 number, since 2×646579634219² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646579634119) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2179982 + ... + 2458755.

It is an arithmetic number, because the mean of its divisors is an integer number (161646103086).

Almost surely, 2^646579634219 is an apocalyptic number.

646579634219 is a deficient number, since it is larger than the sum of its proper divisors (4778125).

646579634219 is a wasteful number, since it uses less digits than its factorization.

646579634219 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4778124.

The product of its digits is 58786560, while the sum is 62.

The spelling of 646579634219 in words is "six hundred forty-six billion, five hundred seventy-nine million, six hundred thirty-four thousand, two hundred nineteen".