66684705 has 32 divisors (see below), whose sum is σ = 111891456. Its totient is φ = 33849024.

The previous prime is 66684649. The next prime is 66684707. The reversal of 66684705 is 50748666.

It is a happy number.

It is not a de Polignac number, because 66684705 - 2¹³ = 66676513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66684707) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 97294 + ... + 97976.

It is an arithmetic number, because the mean of its divisors is an integer number (3496608).

Almost surely, 2^66684705 is an apocalyptic number.

It is an amenable number.

66684705 is a deficient number, since it is larger than the sum of its proper divisors (45206751).

66684705 is a wasteful number, since it uses less digits than its factorization.

66684705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 997.

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

The square root of 66684705 is about 8166.0703523788. The cubic root of 66684705 is about 405.5167006693.

The spelling of 66684705 in words is "sixty-six million, six hundred eighty-four thousand, seven hundred five".