661871695824383 has 16 divisors (see below), whose sum is σ = 725720680482336. Its totient is φ = 598635964429440.

The previous prime is 661871695824379. The next prime is 661871695824389. The reversal of 661871695824383 is 383428596178166.

661871695824383 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 661871695824383 - 2² = 661871695824379 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661871695824389) 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, 113508485 + ... + 119196977.

It is an arithmetic number, because the mean of its divisors is an integer number (45357542530146).

Almost surely, 2^{661871695824383} is an apocalyptic number.

661871695824383 is a deficient number, since it is larger than the sum of its proper divisors (63848984657953).

661871695824383 is a wasteful number, since it uses less digits than its factorization.

661871695824383 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5742394.

The product of its digits is 2508226560, while the sum is 77.

The spelling of 661871695824383 in words is "six hundred sixty-one trillion, eight hundred seventy-one billion, six hundred ninety-five million, eight hundred twenty-four thousand, three hundred eighty-three".