21706214321 has 24 divisors (see below), whose sum is σ = 24722024040. Its totient is φ = 19021291520.

The previous prime is 21706214311. The next prime is 21706214347. The reversal of 21706214321 is 12341260712.

It can be written as a sum of positive squares in 4 ways, for example, as 6405761296 + 15300453025 = 80036^2 + 123695^2 .

It is not a de Polignac number, because 21706214321 - 2¹⁰ = 21706213297 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21706214311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2286641 + ... + 2296113.

It is an arithmetic number, because the mean of its divisors is an integer number (1030084335).

Almost surely, 2^21706214321 is an apocalyptic number.

It is an amenable number.

21706214321 is a deficient number, since it is larger than the sum of its proper divisors (3015809719).

21706214321 is a wasteful number, since it uses less digits than its factorization.

21706214321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10177 (or 10166 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 29.

The spelling of 21706214321 in words is "twenty-one billion, seven hundred six million, two hundred fourteen thousand, three hundred twenty-one".