645877665933 has 16 divisors (see below), whose sum is σ = 866743899840. Its totient is φ = 427806887936.

The previous prime is 645877665931. The next prime is 645877665947. The reversal of 645877665933 is 339566778546.

It is a cyclic number.

It is not a de Polignac number, because 645877665933 - 2¹ = 645877665931 is a prime.

It is a super-3 number, since 3×645877665933³ (a number of 36 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645877665931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 776835 + ... + 1376672.

It is an arithmetic number, because the mean of its divisors is an integer number (54171493740).

Almost surely, 2^645877665933 is an apocalyptic number.

It is an amenable number.

645877665933 is a deficient number, since it is larger than the sum of its proper divisors (220866233907).

645877665933 is a wasteful number, since it uses less digits than its factorization.

645877665933 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2154156.

The product of its digits is 685843200, while the sum is 69.

The spelling of 645877665933 in words is "six hundred forty-five billion, eight hundred seventy-seven million, six hundred sixty-five thousand, nine hundred thirty-three".