21986959 has 8 divisors (see below), whose sum is σ = 22900320. Its totient is φ = 21084000.

The previous prime is 21986957. The next prime is 21986969. The reversal of 21986959 is 95968912.

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

It is a cyclic number.

It is not a de Polignac number, because 21986959 - 2¹ = 21986957 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 (21986953) 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 7 ways as a sum of consecutive naturals, for example, 1869 + ... + 6889.

It is an arithmetic number, because the mean of its divisors is an integer number (2862540).

Almost surely, 2^21986959 is an apocalyptic number.

21986959 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

21986959 is a deficient number, since it is larger than the sum of its proper divisors (913361).

21986959 is a wasteful number, since it uses less digits than its factorization.

21986959 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5201.

The product of its digits is 349920, while the sum is 49.

The square root of 21986959 is about 4689.0253784769. The cubic root of 21986959 is about 280.1485563723.

It can be divided in two parts, 219 and 86959, that added together give a palindrome (87178).

The spelling of 21986959 in words is "twenty-one million, nine hundred eighty-six thousand, nine hundred fifty-nine".