21498732643 has 4 divisors (see below), whose sum is σ = 21720369160. Its totient is φ = 21277096128.

The previous prime is 21498732637. The next prime is 21498732659. The reversal of 21498732643 is 34623789412.

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

It is a cyclic number.

It is not a de Polignac number, because 21498732643 - 2³³ = 12908798051 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21498732443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110818113 + ... + 110818306.

It is an arithmetic number, because the mean of its divisors is an integer number (5430092290).

Almost surely, 2^21498732643 is an apocalyptic number.

21498732643 is a deficient number, since it is larger than the sum of its proper divisors (221636517).

21498732643 is an equidigital number, since it uses as much as digits as its factorization.

21498732643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221636516.

The product of its digits is 1741824, while the sum is 49.

The spelling of 21498732643 in words is "twenty-one billion, four hundred ninety-eight million, seven hundred thirty-two thousand, six hundred forty-three".