66684407 has 16 divisors (see below), whose sum is σ = 69906240. Its totient is φ = 63571200.

The previous prime is 66684377. The next prime is 66684461. The reversal of 66684407 is 70448666.

It is a cyclic number.

It is not a de Polignac number, because 66684407 - 2⁸ = 66684151 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 (66684307) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 385373 + ... + 385545.

It is an arithmetic number, because the mean of its divisors is an integer number (4369140).

Almost surely, 2^66684407 is an apocalyptic number.

66684407 is a deficient number, since it is larger than the sum of its proper divisors (3221833).

66684407 is a wasteful number, since it uses less digits than its factorization.

66684407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 394.

The product of its (nonzero) digits is 193536, while the sum is 41.

The square root of 66684407 is about 8166.0521061282. The cubic root of 66684407 is about 405.5160966120.

The spelling of 66684407 in words is "sixty-six million, six hundred eighty-four thousand, four hundred seven".