21724073165 has 8 divisors (see below), whose sum is σ = 26069749728. Its totient is φ = 17378683920.

The previous prime is 21724073141. The next prime is 21724073177. The reversal of 21724073165 is 56137042712.

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

It is not a de Polignac number, because 21724073165 - 2¹⁰ = 21724072141 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 166274 + ... + 266636.

It is an arithmetic number, because the mean of its divisors is an integer number (3258718716).

Almost surely, 2^21724073165 is an apocalyptic number.

It is an amenable number.

21724073165 is a deficient number, since it is larger than the sum of its proper divisors (4345676563).

21724073165 is a wasteful number, since it uses less digits than its factorization.

21724073165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143659.

The product of its (nonzero) digits is 70560, while the sum is 38.

The spelling of 21724073165 in words is "twenty-one billion, seven hundred twenty-four million, seventy-three thousand, one hundred sixty-five".