21703223721 has 8 divisors (see below), whose sum is σ = 29871103744. Its totient is φ = 14002079760.

The previous prime is 21703223713. The next prime is 21703223743. The reversal of 21703223721 is 12732230712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21703223721 - 2³ = 21703223713 is a prime.

It is a super-3 number, since 3×21703223721³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21703223021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 116683906 + ... + 116684091.

It is an arithmetic number, because the mean of its divisors is an integer number (3733887968).

Almost surely, 2^21703223721 is an apocalyptic number.

It is an amenable number.

21703223721 is a deficient number, since it is larger than the sum of its proper divisors (8167880023).

21703223721 is a wasteful number, since it uses less digits than its factorization.

21703223721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233368031.

The product of its (nonzero) digits is 7056, while the sum is 30.

The spelling of 21703223721 in words is "twenty-one billion, seven hundred three million, two hundred twenty-three thousand, seven hundred twenty-one".