66208654138 has 32 divisors (see below), whose sum is σ = 114749794368. Its totient is φ = 28315833600.

The previous prime is 66208654097. The next prime is 66208654157. The reversal of 66208654138 is 83145680266.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 66208654091 and 66208654100.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1271128 + ... + 1322188.

It is an arithmetic number, because the mean of its divisors is an integer number (3585931074).

Almost surely, 2^66208654138 is an apocalyptic number.

66208654138 is a deficient number, since it is larger than the sum of its proper divisors (48541140230).

66208654138 is a wasteful number, since it uses less digits than its factorization.

66208654138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54558.

The product of its (nonzero) digits is 1658880, while the sum is 49.

The spelling of 66208654138 in words is "sixty-six billion, two hundred eight million, six hundred fifty-four thousand, one hundred thirty-eight".