66508775 has 6 divisors (see below), whose sum is σ = 82470912. Its totient is φ = 53207000.

The previous prime is 66508763. The next prime is 66508789. The reversal of 66508775 is 57780566.

It is a de Polignac number, because none of the positive numbers 2^k-66508775 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1330151 + ... + 1330200.

It is an arithmetic number, because the mean of its divisors is an integer number (13745152).

Almost surely, 2^66508775 is an apocalyptic number.

66508775 is a deficient number, since it is larger than the sum of its proper divisors (15962137).

66508775 is a wasteful number, since it uses less digits than its factorization.

66508775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2660361 (or 2660356 counting only the distinct ones).

The product of its (nonzero) digits is 352800, while the sum is 44.

The square root of 66508775 is about 8155.2912271727. The cubic root of 66508775 is about 405.1597703219.

The spelling of 66508775 in words is "sixty-six million, five hundred eight thousand, seven hundred seventy-five".