66551656 has 16 divisors (see below), whose sum is σ = 125023140. Its totient is φ = 33212160.

The previous prime is 66551647. The next prime is 66551657. The reversal of 66551656 is 65615566.

It can be written as a sum of positive squares in 2 ways, for example, as 59444100 + 7107556 = 7710^2 + 2666^2 .

It is not an unprimeable number, because it can be changed into a prime (66551657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3361 + ... + 12016.

Almost surely, 2^66551656 is an apocalyptic number.

It is an amenable number.

66551656 is a deficient number, since it is larger than the sum of its proper divisors (58471484).

66551656 is a wasteful number, since it uses less digits than its factorization.

66551656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15924 (or 15920 counting only the distinct ones).

The product of its digits is 162000, while the sum is 40.

The square root of 66551656 is about 8157.9198328986. The cubic root of 66551656 is about 405.2468261207.

The spelling of 66551656 in words is "sixty-six million, five hundred fifty-one thousand, six hundred fifty-six".