66651538 has 8 divisors (see below), whose sum is σ = 100894860. Its totient is φ = 33019920.

The previous prime is 66651521. The next prime is 66651547. The reversal of 66651538 is 83515666.

66651538 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 62837329 + 3814209 = 7927^2 + 1953^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 66651538.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 152653 + ... + 153088.

Almost surely, 2^66651538 is an apocalyptic number.

66651538 is a deficient number, since it is larger than the sum of its proper divisors (34243322).

66651538 is a wasteful number, since it uses less digits than its factorization.

66651538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305852.

The product of its digits is 129600, while the sum is 40.

The square root of 66651538 is about 8164.0393188666. The cubic root of 66651538 is about 405.4494588489.

The spelling of 66651538 in words is "sixty-six million, six hundred fifty-one thousand, five hundred thirty-eight".