66655388 has 6 divisors (see below), whose sum is σ = 116646936. Its totient is φ = 33327692.

The previous prime is 66655387. The next prime is 66655409. The reversal of 66655388 is 88355666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66655387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8331920 + ... + 8331927.

It is an arithmetic number, because the mean of its divisors is an integer number (19441156).

Almost surely, 2^66655388 is an apocalyptic number.

It is an amenable number.

66655388 is a deficient number, since it is larger than the sum of its proper divisors (49991548).

66655388 is a wasteful number, since it uses less digits than its factorization.

66655388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16663851 (or 16663849 counting only the distinct ones).

The product of its digits is 1036800, while the sum is 47.

The square root of 66655388 is about 8164.2751056049. The cubic root of 66655388 is about 405.4572653723.

The spelling of 66655388 in words is "sixty-six million, six hundred fifty-five thousand, three hundred eighty-eight".