66128834 has 4 divisors (see below), whose sum is σ = 99193254. Its totient is φ = 33064416.

The previous prime is 66128807. The next prime is 66128837. The reversal of 66128834 is 43882166.

It is a happy number.

66128834 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 57805609 + 8323225 = 7603^2 + 2885^2 .

It is not an unprimeable number, because it can be changed into a prime (66128837) by changing a digit.

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 as a sum of consecutive naturals, namely, 16532207 + ... + 16532210.

Almost surely, 2^66128834 is an apocalyptic number.

66128834 is a deficient number, since it is larger than the sum of its proper divisors (33064420).

66128834 is a wasteful number, since it uses less digits than its factorization.

66128834 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33064419.

The product of its digits is 55296, while the sum is 38.

The square root of 66128834 is about 8131.9637234803. The cubic root of 66128834 is about 404.3867852488.

The spelling of 66128834 in words is "sixty-six million, one hundred twenty-eight thousand, eight hundred thirty-four".