66905611 has 4 divisors (see below), whose sum is σ = 66972672. Its totient is φ = 66838552.

The previous prime is 66905603. The next prime is 66905633. The reversal of 66905611 is 11650966.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66905611 - 2³ = 66905603 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66905681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32011 + ... + 34036.

It is an arithmetic number, because the mean of its divisors is an integer number (16743168).

Almost surely, 2^66905611 is an apocalyptic number.

66905611 is a deficient number, since it is larger than the sum of its proper divisors (67061).

66905611 is a wasteful number, since it uses less digits than its factorization.

66905611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67060.

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 66905611 is about 8179.5850139234. The cubic root of 66905611 is about 405.9639913222.

The spelling of 66905611 in words is "sixty-six million, nine hundred five thousand, six hundred eleven".