66646730 has 16 divisors (see below), whose sum is σ = 122890824. Its totient is φ = 26008320.

The previous prime is 66646717. The next prime is 66646739. The reversal of 66646730 is 3764666.

It can be written as a sum of positive squares in 4 ways, for example, as 57350329 + 9296401 = 7573^2 + 3049^2 .

It is not an unprimeable number, because it can be changed into a prime (66646739) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 80867 + ... + 81686.

Almost surely, 2^66646730 is an apocalyptic number.

66646730 is a deficient number, since it is larger than the sum of its proper divisors (56244094).

66646730 is a wasteful number, since it uses less digits than its factorization.

66646730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162601.

The product of its (nonzero) digits is 108864, while the sum is 38.

The square root of 66646730 is about 8163.7448514759. The cubic root of 66646730 is about 405.4397093971.

It can be divided in two parts, 66646 and 730, that added together give a palindrome (67376).

The spelling of 66646730 in words is "sixty-six million, six hundred forty-six thousand, seven hundred thirty".