188364217721 has 8 divisors (see below), whose sum is σ = 191922545088. Its totient is φ = 184831038000.

The previous prime is 188364217703. The next prime is 188364217747. The reversal of 188364217721 is 127712463881.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-188364217721 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 188364217721.

It is not an unprimeable number, because it can be changed into a prime (188364216721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6271790 + ... + 6301751.

It is an arithmetic number, because the mean of its divisors is an integer number (23990318136).

Almost surely, 2^188364217721 is an apocalyptic number.

It is an amenable number.

188364217721 is a deficient number, since it is larger than the sum of its proper divisors (3558327367).

188364217721 is a wasteful number, since it uses less digits than its factorization.

188364217721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12573823.

The product of its digits is 903168, while the sum is 50.

The spelling of 188364217721 in words is "one hundred eighty-eight billion, three hundred sixty-four million, two hundred seventeen thousand, seven hundred twenty-one".