66239739 has 12 divisors (see below), whose sum is σ = 96628272. Its totient is φ = 43722000.

The previous prime is 66239699. The next prime is 66239749. The reversal of 66239739 is 93793266.

It is not a de Polignac number, because 66239739 - 2¹⁹ = 65715451 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66239694 and 66239703.

It is not an unprimeable number, because it can be changed into a prime (66239749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 35527 + ... + 37344.

It is an arithmetic number, because the mean of its divisors is an integer number (8052356).

Almost surely, 2^66239739 is an apocalyptic number.

66239739 is a deficient number, since it is larger than the sum of its proper divisors (30388533).

66239739 is a wasteful number, since it uses less digits than its factorization.

66239739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72978 (or 72975 counting only the distinct ones).

The product of its digits is 367416, while the sum is 45.

The square root of 66239739 is about 8138.7799454218. The cubic root of 66239739 is about 404.6127253577.

It can be divided in two parts, 662 and 39739, that added together give a square (40401 = 201²).

The spelling of 66239739 in words is "sixty-six million, two hundred thirty-nine thousand, seven hundred thirty-nine".