21350584643 has 4 divisors (see below), whose sum is σ = 21354733128. Its totient is φ = 21346436160.

The previous prime is 21350584637. The next prime is 21350584649. The reversal of 21350584643 is 34648505312.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21350584637) and next prime (21350584649).

It is a cyclic number.

It is not a de Polignac number, because 21350584643 - 2¹⁶ = 21350519107 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 21350584643.

It is not an unprimeable number, because it can be changed into a prime (21350584649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2066513 + ... + 2076818.

It is an arithmetic number, because the mean of its divisors is an integer number (5338683282).

Almost surely, 2^21350584643 is an apocalyptic number.

21350584643 is a deficient number, since it is larger than the sum of its proper divisors (4148485).

21350584643 is an equidigital number, since it uses as much as digits as its factorization.

21350584643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4148484.

The product of its (nonzero) digits is 345600, while the sum is 41.

The spelling of 21350584643 in words is "twenty-one billion, three hundred fifty million, five hundred eighty-four thousand, six hundred forty-three".