1806602121801 has 27 divisors (see below), whose sum is σ = 2682192075381. Its totient is φ = 1171753249824.

The previous prime is 1806602121773. The next prime is 1806602121827. The reversal of 1806602121801 is 1081212066081.

The square root of 1806602121801 is 1344099.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 1552005182025 + 254596939776 = 1245795^2 + 504576^2 .

It is not a de Polignac number, because 1806602121801 - 2¹⁹ = 1806601597513 is a prime.

It is a super-2 number, since 2×1806602121801² (a number of 25 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1806602121851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 149188935 + ... + 149201043.

Almost surely, 2^{1806602121801} is an apocalyptic number.

1806602121801 is the 1344099-th square number.

1806602121801 is the 672050-th centered octagonal number.

It is an amenable number.

1806602121801 is a deficient number, since it is larger than the sum of its proper divisors (875589953580).

1806602121801 is an frugal number, since it uses more digits than its factorization.

1806602121801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24298 (or 12149 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

Multiplying 1806602121801 by its sum of digits (36), we get a square (65037676384836 = 8064594²).

Adding to 1806602121801 its reverse (1081212066081), we get a palindrome (2887814187882).

The spelling of 1806602121801 in words is "one trillion, eight hundred six billion, six hundred two million, one hundred twenty-one thousand, eight hundred one".