66856777630 has 48 divisors (see below), whose sum is σ = 127146826224. Its totient is φ = 25307781120.

The previous prime is 66856777621. The next prime is 66856777643. The reversal of 66856777630 is 3677765866.

It is a super-3 number, since 3×66856777630³ (a number of 33 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3495774 + ... + 3514846.

It is an arithmetic number, because the mean of its divisors is an integer number (2648892213).

Almost surely, 2^66856777630 is an apocalyptic number.

66856777630 is a deficient number, since it is larger than the sum of its proper divisors (60290048594).

66856777630 is a wasteful number, since it uses less digits than its factorization.

66856777630 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20089 (or 20070 counting only the distinct ones).

The product of its (nonzero) digits is 53343360, while the sum is 61.

The spelling of 66856777630 in words is "sixty-six billion, eight hundred fifty-six million, seven hundred seventy-seven thousand, six hundred thirty".