66439901 has 8 divisors (see below), whose sum is σ = 74439264. Its totient is φ = 58767120.

The previous prime is 66439873. The next prime is 66439963. The reversal of 66439901 is 10993466.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66439901 - 2²² = 62245597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66439981) 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, 81215 + ... + 82028.

It is an arithmetic number, because the mean of its divisors is an integer number (9304908).

Almost surely, 2^66439901 is an apocalyptic number.

It is an amenable number.

66439901 is a deficient number, since it is larger than the sum of its proper divisors (7999363).

66439901 is a wasteful number, since it uses less digits than its factorization.

66439901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163291.

The product of its (nonzero) digits is 34992, while the sum is 38.

The square root of 66439901 is about 8151.0674761040. The cubic root of 66439901 is about 405.0198659157.

The spelling of 66439901 in words is "sixty-six million, four hundred thirty-nine thousand, nine hundred one".