646663769911 has 16 divisors (see below), whose sum is σ = 676412489088. Its totient is φ = 617706777600.

The previous prime is 646663769893. The next prime is 646663770007. The reversal of 646663769911 is 119967366646.

It is a cyclic number.

It is not a de Polignac number, because 646663769911 - 2⁹ = 646663769399 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646663709911) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 378495 + ... + 1198576.

It is an arithmetic number, because the mean of its divisors is an integer number (42275780568).

Almost surely, 2^646663769911 is an apocalyptic number.

646663769911 is a deficient number, since it is larger than the sum of its proper divisors (29748719177).

646663769911 is a wasteful number, since it uses less digits than its factorization.

646663769911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1577322.

The product of its digits is 52907904, while the sum is 64.

The spelling of 646663769911 in words is "six hundred forty-six billion, six hundred sixty-three million, seven hundred sixty-nine thousand, nine hundred eleven".