66238739 has 12 divisors (see below), whose sum is σ = 78934968. Its totient is φ = 55389600.

The previous prime is 66238721. The next prime is 66238751. The reversal of 66238739 is 93783266.

It is a de Polignac number, because none of the positive numbers 2^k-66238739 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66238739.

It is not an unprimeable number, because it can be changed into a prime (66238439) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14477 + ... + 18494.

It is an arithmetic number, because the mean of its divisors is an integer number (6577914).

Almost surely, 2^66238739 is an apocalyptic number.

66238739 is a deficient number, since it is larger than the sum of its proper divisors (12696229).

66238739 is a wasteful number, since it uses less digits than its factorization.

66238739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33026 (or 33019 counting only the distinct ones).

The product of its digits is 326592, while the sum is 44.

The square root of 66238739 is about 8138.7185109205. The cubic root of 66238739 is about 404.6106892448.

The spelling of 66238739 in words is "sixty-six million, two hundred thirty-eight thousand, seven hundred thirty-nine".