18202689339721 has 16 divisors (see below), whose sum is σ = 18876607117200. Its totient is φ = 17531901370368.

The previous prime is 18202689339677. The next prime is 18202689339797. The reversal of 18202689339721 is 12793398620281.

It can be written as a sum of positive squares in 8 ways, for example, as 9561323595321 + 8641365744400 = 3092139^2 + 2939620^2 .

It is a cyclic number.

It is not a de Polignac number, because 18202689339721 - 2³⁵ = 18168329601353 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18202689339721.

It is not an unprimeable number, because it can be changed into a prime (18202689339221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21213925 + ... + 22055293.

It is an arithmetic number, because the mean of its divisors is an integer number (1179787944825).

Almost surely, 2^{18202689339721} is an apocalyptic number.

It is an amenable number.

18202689339721 is a deficient number, since it is larger than the sum of its proper divisors (673917777479).

18202689339721 is a wasteful number, since it uses less digits than its factorization.

18202689339721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 843228.

The product of its (nonzero) digits is 15676416, while the sum is 61.

The spelling of 18202689339721 in words is "eighteen trillion, two hundred two billion, six hundred eighty-nine million, three hundred thirty-nine thousand, seven hundred twenty-one".