66626838728 has 16 divisors (see below), whose sum is σ = 124931237760. Its totient is φ = 33311842000.

The previous prime is 66626838697. The next prime is 66626838757. The reversal of 66626838728 is 82783862666.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6848 + ... + 365103.

It is an arithmetic number, because the mean of its divisors is an integer number (7808202360).

Almost surely, 2^66626838728 is an apocalyptic number.

It is an amenable number.

66626838728 is a deficient number, since it is larger than the sum of its proper divisors (58304399032).

66626838728 is a wasteful number, since it uses less digits than its factorization.

66626838728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 394348 (or 394344 counting only the distinct ones).

The product of its digits is 55738368, while the sum is 62.

The spelling of 66626838728 in words is "sixty-six billion, six hundred twenty-six million, eight hundred thirty-eight thousand, seven hundred twenty-eight".