66655444 has 6 divisors (see below), whose sum is σ = 116647034. Its totient is φ = 33327720.

The previous prime is 66655441. The next prime is 66655469. The reversal of 66655444 is 44455666.

It can be written as a sum of positive squares in only one way, i.e., 60652944 + 6002500 = 7788^2 + 2450^2 .

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 66655397 and 66655406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66655441) by changing a digit.

It is an upside-down number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8331927 + ... + 8331934.

Almost surely, 2^66655444 is an apocalyptic number.

It is an amenable number.

66655444 is a deficient number, since it is larger than the sum of its proper divisors (49991590).

66655444 is a wasteful number, since it uses less digits than its factorization.

66655444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16663865 (or 16663863 counting only the distinct ones).

The product of its digits is 345600, while the sum is 40.

The square root of 66655444 is about 8164.2785351799. The cubic root of 66655444 is about 405.4573789195.

The spelling of 66655444 in words is "sixty-six million, six hundred fifty-five thousand, four hundred forty-four".