21985159 has 8 divisors (see below), whose sum is σ = 25217568. Its totient is φ = 18775680.

The previous prime is 21985153. The next prime is 21985189. The reversal of 21985159 is 95158912.

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

It is not a de Polignac number, because 21985159 - 2³ = 21985151 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 (21985151) 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, 3622 + ... + 7555.

It is an arithmetic number, because the mean of its divisors is an integer number (3152196).

Almost surely, 2^21985159 is an apocalyptic number.

21985159 is a deficient number, since it is larger than the sum of its proper divisors (3232409).

21985159 is a wasteful number, since it uses less digits than its factorization.

21985159 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11465.

The product of its digits is 32400, while the sum is 40.

The square root of 21985159 is about 4688.8334370075. The cubic root of 21985159 is about 280.1409112168.

The spelling of 21985159 in words is "twenty-one million, nine hundred eighty-five thousand, one hundred fifty-nine".