21086159 has 4 divisors (see below), whose sum is σ = 21279720. Its totient is φ = 20892600.

The previous prime is 21086141. The next prime is 21086179. The reversal of 21086159 is 95168012.

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

It is a cyclic number.

It is not a de Polignac number, because 21086159 - 2¹² = 21082063 is a prime.

It is a super-2 number, since 2×21086159² = 889252202746562, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21086129) 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, 96617 + ... + 96834.

It is an arithmetic number, because the mean of its divisors is an integer number (5319930).

Almost surely, 2^21086159 is an apocalyptic number.

21086159 is a deficient number, since it is larger than the sum of its proper divisors (193561).

21086159 is a wasteful number, since it uses less digits than its factorization.

21086159 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193560.

The product of its (nonzero) digits is 4320, while the sum is 32.

The square root of 21086159 is about 4591.9667899496. The cubic root of 21086159 is about 276.2692141451.

The spelling of 21086159 in words is "twenty-one million, eighty-six thousand, one hundred fifty-nine".