66628749 has 32 divisors (see below), whose sum is σ = 100400256. Its totient is φ = 38949120.

The previous prime is 66628739. The next prime is 66628781. The reversal of 66628749 is 94782666.

It is not a de Polignac number, because 66628749 - 2⁴ = 66628733 is a prime.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 66628698 and 66628707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66628739) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 240399 + ... + 240675.

It is an arithmetic number, because the mean of its divisors is an integer number (3137508).

Almost surely, 2^66628749 is an apocalyptic number.

It is an amenable number.

66628749 is a deficient number, since it is larger than the sum of its proper divisors (33771507).

66628749 is a wasteful number, since it uses less digits than its factorization.

With its successor (66628750) it forms an eRAP, since the sums of their prime factors are consecutive (525 and 526).

66628749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 525.

The product of its digits is 870912, while the sum is 48.

The square root of 66628749 is about 8162.6435056298. The cubic root of 66628749 is about 405.4032441565.

The spelling of 66628749 in words is "sixty-six million, six hundred twenty-eight thousand, seven hundred forty-nine".