71661666 has 8 divisors (see below), whose sum is σ = 143323344. Its totient is φ = 23887220.

The previous prime is 71661661. The next prime is 71661679. The reversal of 71661666 is 66616617.

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

71661666 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (71661661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5971800 + ... + 5971811.

It is an arithmetic number, because the mean of its divisors is an integer number (17915418).

Almost surely, 2^71661666 is an apocalyptic number.

71661666 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

71661666 is a wasteful number, since it uses less digits than its factorization.

71661666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11943616.

The product of its digits is 54432, while the sum is 39.

The square root of 71661666 is about 8465.3213760613. The cubic root of 71661666 is about 415.3641087640.

It can be divided in two parts, 71661 and 666, that added together give a palindrome (72327).

The spelling of 71661666 in words is "seventy-one million, six hundred sixty-one thousand, six hundred sixty-six".