66581207 has 8 divisors (see below), whose sum is σ = 83010432. Its totient is φ = 51881400.

The previous prime is 66581201. The next prime is 66581209. The reversal of 66581207 is 70218566.

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 66581207 - 2⁴ = 66581191 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66581201) 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, 432269 + ... + 432422.

It is an arithmetic number, because the mean of its divisors is an integer number (10376304).

Almost surely, 2^66581207 is an apocalyptic number.

66581207 is a deficient number, since it is larger than the sum of its proper divisors (16429225).

66581207 is a wasteful number, since it uses less digits than its factorization.

66581207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 864709.

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 66581207 is about 8159.7308166385. The cubic root of 66581207 is about 405.3067979663.

The spelling of 66581207 in words is "sixty-six million, five hundred eighty-one thousand, two hundred seven".