21988159 has 2 divisors, whose sum is σ = 21988160. Its totient is φ = 21988158.

The previous prime is 21988147. The next prime is 21988171. The reversal of 21988159 is 95188912.

It is a balanced prime because it is at equal distance from previous prime (21988147) and next prime (21988171).

It is a cyclic number.

It is not a de Polignac number, because 21988159 - 2²¹ = 19891007 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21988139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10994079 + 10994080.

It is an arithmetic number, because the mean of its divisors is an integer number (10994080).

Almost surely, 2^21988159 is an apocalyptic number.

21988159 is a deficient number, since it is larger than the sum of its proper divisors (1).

21988159 is an equidigital number, since it uses as much as digits as its factorization.

21988159 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51840, while the sum is 43.

The square root of 21988159 is about 4689.1533350915. The cubic root of 21988159 is about 280.1536529108.

The spelling of 21988159 in words is "twenty-one million, nine hundred eighty-eight thousand, one hundred fifty-nine".