66439872 has 56 divisors (see below), whose sum is σ = 195326000. Its totient is φ = 22146048.

The previous prime is 66439871. The next prime is 66439873. The reversal of 66439872 is 27893466.

It is an interprime number because it is at equal distance from previous prime (66439871) and next prime (66439873).

It is not an unprimeable number, because it can be changed into a prime (66439871) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17497 + ... + 20952.

Almost surely, 2^66439872 is an apocalyptic number.

It is an amenable number.

66439872 is an abundant number, since it is smaller than the sum of its proper divisors (128886128).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66439872 is a wasteful number, since it uses less digits than its factorization.

66439872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38470 (or 38454 counting only the distinct ones).

The product of its digits is 435456, while the sum is 45.

The square root of 66439872 is about 8151.0656971957. The cubic root of 66439872 is about 405.0198069874.

The spelling of 66439872 in words is "sixty-six million, four hundred thirty-nine thousand, eight hundred seventy-two".