646027720646 has 16 divisors (see below), whose sum is σ = 1208155737600. Its totient is φ = 251699111880.

The previous prime is 646027720627. The next prime is 646027720649.

646027720646 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 646027720594 and 646027720603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646027720649) 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, 2097492446 + ... + 2097492753.

It is an arithmetic number, because the mean of its divisors is an integer number (75509733600).

Almost surely, 2^646027720646 is an apocalyptic number.

646027720646 is a deficient number, since it is larger than the sum of its proper divisors (562128016954).

646027720646 is a wasteful number, since it uses less digits than its factorization.

646027720646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4194985219.

The product of its (nonzero) digits is 4064256, while the sum is 50.

The spelling of 646027720646 in words is "six hundred forty-six billion, twenty-seven million, seven hundred twenty thousand, six hundred forty-six".