66658407 has 8 divisors (see below), whose sum is σ = 89741184. Its totient is φ = 44007288.

The previous prime is 66658399. The next prime is 66658409. The reversal of 66658407 is 70485666.

It is a happy number.

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

It is not a de Polignac number, because 66658407 - 2³ = 66658399 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66658409) 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, 107553 + ... + 108170.

It is an arithmetic number, because the mean of its divisors is an integer number (11217648).

Almost surely, 2^66658407 is an apocalyptic number.

66658407 is a deficient number, since it is larger than the sum of its proper divisors (23082777).

66658407 is a wasteful number, since it uses less digits than its factorization.

66658407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215829.

The product of its (nonzero) digits is 241920, while the sum is 42.

The square root of 66658407 is about 8164.4599943903. The cubic root of 66658407 is about 405.4633866929.

The spelling of 66658407 in words is "sixty-six million, six hundred fifty-eight thousand, four hundred seven".