66243639 has 48 divisors (see below), whose sum is σ = 113861376. Its totient is φ = 33868800.

The previous prime is 66243629. The next prime is 66243641. The reversal of 66243639 is 93634266.

It is not a de Polignac number, because 66243639 - 2⁴ = 66243623 is a prime.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 66243597 and 66243606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66243629) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 114519 + ... + 115095.

It is an arithmetic number, because the mean of its divisors is an integer number (2372112).

Almost surely, 2^66243639 is an apocalyptic number.

66243639 is a deficient number, since it is larger than the sum of its proper divisors (47617737).

66243639 is a wasteful number, since it uses less digits than its factorization.

66243639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 676 (or 669 counting only the distinct ones).

The product of its digits is 139968, while the sum is 39.

The square root of 66243639 is about 8139.0195355460. The cubic root of 66243639 is about 404.6206660022.

The spelling of 66243639 in words is "sixty-six million, two hundred forty-three thousand, six hundred thirty-nine".