21810684343 has 8 divisors (see below), whose sum is σ = 25435200800. Its totient is φ = 18694872000.

The previous prime is 21810684323. The next prime is 21810684377. The reversal of 21810684343 is 34348601812.

It is not a de Polignac number, because 21810684343 - 2⁹ = 21810683831 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21810684296 and 21810684305.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21810684323) 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, 31793658 + ... + 31794343.

It is an arithmetic number, because the mean of its divisors is an integer number (3179400100).

Almost surely, 2^21810684343 is an apocalyptic number.

21810684343 is a deficient number, since it is larger than the sum of its proper divisors (3624516457).

21810684343 is an frugal number, since it uses more digits than its factorization.

21810684343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63588022 (or 63588008 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 40.

The spelling of 21810684343 in words is "twenty-one billion, eight hundred ten million, six hundred eighty-four thousand, three hundred forty-three".