66388534 has 16 divisors (see below), whose sum is σ = 106126848. Its totient is φ = 31074472.

The previous prime is 66388507. The next prime is 66388537. The reversal of 66388534 is 43588366.

66388534 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66388537) 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 in 7 ways as a sum of consecutive naturals, for example, 13192 + ... + 17515.

It is an arithmetic number, because the mean of its divisors is an integer number (6632928).

Almost surely, 2^66388534 is an apocalyptic number.

66388534 is a deficient number, since it is larger than the sum of its proper divisors (39738314).

66388534 is a wasteful number, since it uses less digits than its factorization.

66388534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30779.

The product of its digits is 414720, while the sum is 43.

The square root of 66388534 is about 8147.9159298559. The cubic root of 66388534 is about 404.9154606861.

The spelling of 66388534 in words is "sixty-six million, three hundred eighty-eight thousand, five hundred thirty-four".