21645652343 has 6 divisors (see below), whose sum is σ = 25179636456. Its totient is φ = 18553416252.

The previous prime is 21645652313. The next prime is 21645652349. The reversal of 21645652343 is 34325654612.

It is a de Polignac number, because none of the positive numbers 2^k-21645652343 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 21645652343.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21645652349) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 220873955 + ... + 220874052.

It is an arithmetic number, because the mean of its divisors is an integer number (4196606076).

Almost surely, 2^21645652343 is an apocalyptic number.

21645652343 is a deficient number, since it is larger than the sum of its proper divisors (3533984113).

21645652343 is an equidigital number, since it uses as much as digits as its factorization.

21645652343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 441748021 (or 441748014 counting only the distinct ones).

The product of its digits is 518400, while the sum is 41.

The spelling of 21645652343 in words is "twenty-one billion, six hundred forty-five million, six hundred fifty-two thousand, three hundred forty-three".