1808647536421 has 6 divisors (see below), whose sum is σ = 1988017540166. Its totient is φ = 1644225033000.

The previous prime is 1808647536403. The next prime is 1808647536439. The reversal of 1808647536421 is 1246357468081.

It is an interprime number because it is at equal distance from previous prime (1808647536403) and next prime (1808647536439).

It can be written as a sum of positive squares in only one way, i.e., 989597196225 + 819050340196 = 994785^2 + 905014^2 .

It is not a de Polignac number, because 1808647536421 - 2⁹ = 1808647535909 is a prime.

It is a super-2 number, since 2×1808647536421² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1808647536481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7473750030 + ... + 7473750271.

Almost surely, 2^{1808647536421} is an apocalyptic number.

1808647536421 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1808647536421 is a deficient number, since it is larger than the sum of its proper divisors (179370003745).

1808647536421 is a wasteful number, since it uses less digits than its factorization.

1808647536421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14947500323 (or 14947500312 counting only the distinct ones).

The product of its (nonzero) digits is 7741440, while the sum is 55.

The spelling of 1808647536421 in words is "one trillion, eight hundred eight billion, six hundred forty-seven million, five hundred thirty-six thousand, four hundred twenty-one".