21599159 has 4 divisors (see below), whose sum is σ = 21790416. Its totient is φ = 21407904.

The previous prime is 21599117. The next prime is 21599177. The reversal of 21599159 is 95199512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21599159 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 (21599059) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 95459 + ... + 95684.

It is an arithmetic number, because the mean of its divisors is an integer number (5447604).

Almost surely, 2^21599159 is an apocalyptic number.

21599159 is a deficient number, since it is larger than the sum of its proper divisors (191257).

21599159 is a wasteful number, since it uses less digits than its factorization.

21599159 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191256.

The product of its digits is 36450, while the sum is 41.

The square root of 21599159 is about 4647.4895373739. The cubic root of 21599159 is about 278.4917155474.

The spelling of 21599159 in words is "twenty-one million, five hundred ninety-nine thousand, one hundred fifty-nine".