66783888945 has 24 divisors (see below), whose sum is σ = 115768501056. Its totient is φ = 35615071008.

The previous prime is 66783888931. The next prime is 66783888959. The reversal of 66783888945 is 54988838766.

66783888945 is a `hidden beast` number, since 66 + 78 + 388 + 89 + 45 = 666.

It is an interprime number because it is at equal distance from previous prime (66783888931) and next prime (66783888959).

It is not a de Polignac number, because 66783888945 - 2⁶ = 66783888881 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 541084 + ... + 652946.

It is an arithmetic number, because the mean of its divisors is an integer number (4823687544).

Almost surely, 2^66783888945 is an apocalyptic number.

It is an amenable number.

66783888945 is a deficient number, since it is larger than the sum of its proper divisors (48984612111).

66783888945 is a wasteful number, since it uses less digits than its factorization.

66783888945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125141 (or 125138 counting only the distinct ones).

The product of its digits is 557383680, while the sum is 72.

The spelling of 66783888945 in words is "sixty-six billion, seven hundred eighty-three million, eight hundred eighty-eight thousand, nine hundred forty-five".