21230559 has 16 divisors (see below), whose sum is σ = 35946240. Its totient is φ = 12131640.

The previous prime is 21230557. The next prime is 21230591. The reversal of 21230559 is 95503212.

It is not a de Polignac number, because 21230559 - 2¹ = 21230557 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21230551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55977 + ... + 56354.

It is an arithmetic number, because the mean of its divisors is an integer number (2246640).

Almost surely, 2^21230559 is an apocalyptic number.

21230559 is a deficient number, since it is larger than the sum of its proper divisors (14715681).

21230559 is a wasteful number, since it uses less digits than its factorization.

21230559 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112347 (or 112341 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 27.

The square root of 21230559 is about 4607.6630736199. The cubic root of 21230559 is about 276.8984192254.

The spelling of 21230559 in words is "twenty-one million, two hundred thirty thousand, five hundred fifty-nine".