21097343843 has 18 divisors (see below), whose sum is σ = 21675698604. Its totient is φ = 20534229144.

The previous prime is 21097343821. The next prime is 21097343863. The reversal of 21097343843 is 34834379012.

It is a de Polignac number, because none of the positive numbers 2^k-21097343843 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21097343794 and 21097343803.

It is not an unprimeable number, because it can be changed into a prime (21097343803) 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 17 ways as a sum of consecutive naturals, for example, 47623580 + ... + 47624022.

It is an arithmetic number, because the mean of its divisors is an integer number (1204205478).

Almost surely, 2^21097343843 is an apocalyptic number.

21097343843 is a deficient number, since it is larger than the sum of its proper divisors (578354761).

21097343843 is an frugal number, since it uses more digits than its factorization.

21097343843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 783 (or 613 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 44.

The spelling of 21097343843 in words is "twenty-one billion, ninety-seven million, three hundred forty-three thousand, eight hundred forty-three".