21712159 has 8 divisors (see below), whose sum is σ = 25034400. Its totient is φ = 18445056.

The previous prime is 21712153. The next prime is 21712169. The reversal of 21712159 is 95121712.

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

It is not a de Polignac number, because 21712159 - 2³ = 21712151 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21712151) 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, 12934 + ... + 14515.

It is an arithmetic number, because the mean of its divisors is an integer number (3129300).

Almost surely, 2^21712159 is an apocalyptic number.

21712159 is a deficient number, since it is larger than the sum of its proper divisors (3322241).

21712159 is a wasteful number, since it uses less digits than its factorization.

21712159 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27569.

The product of its digits is 1260, while the sum is 28.

The square root of 21712159 is about 4659.6307793644. The cubic root of 21712159 is about 278.9765313867.

The spelling of 21712159 in words is "twenty-one million, seven hundred twelve thousand, one hundred fifty-nine".