71222216715666 has 16 divisors (see below), whose sum is σ = 158271592701600. Its totient is φ = 23740738905204.

The previous prime is 71222216715649. The next prime is 71222216715787. The reversal of 71222216715666 is 66651761222217.

It is a Harshad number since it is a multiple of its sum of digits (54), and also a Moran number because the ratio is a prime number: 1318929939179 = 71222216715666 / (7 + 1 + 2 + 2 + 2 + 2 + 1 + 6 + 7 + 1 + 5 + 6 + 6 + 6).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 659464969536 + ... + 659464969643.

It is an arithmetic number, because the mean of its divisors is an integer number (9891974543850).

Almost surely, 2^{71222216715666} is an apocalyptic number.

71222216715666 is an abundant number, since it is smaller than the sum of its proper divisors (87049375985934).

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

71222216715666 is a wasteful number, since it uses less digits than its factorization.

71222216715666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1318929939190 (or 1318929939184 counting only the distinct ones).

The product of its digits is 5080320, while the sum is 54.

The spelling of 71222216715666 in words is "seventy-one trillion, two hundred twenty-two billion, two hundred sixteen million, seven hundred fifteen thousand, six hundred sixty-six".