66399651506 has 16 divisors (see below), whose sum is σ = 102364742304. Its totient is φ = 32284873824.

The previous prime is 66399651473. The next prime is 66399651523. The reversal of 66399651506 is 60515699366.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1681115 + ... + 1720158.

It is an arithmetic number, because the mean of its divisors is an integer number (6397796394).

Almost surely, 2^66399651506 is an apocalyptic number.

66399651506 is a deficient number, since it is larger than the sum of its proper divisors (35965090798).

66399651506 is a wasteful number, since it uses less digits than its factorization.

66399651506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3401545.

The product of its (nonzero) digits is 7873200, while the sum is 56.

The spelling of 66399651506 in words is "sixty-six billion, three hundred ninety-nine million, six hundred fifty-one thousand, five hundred six".