21986550 has 36 divisors (see below), whose sum is σ = 59071740. Its totient is φ = 5862960.

The previous prime is 21986543. The next prime is 21986563. The reversal of 21986550 is 5568912.

It is a happy number.

21986550 is a `hidden beast` number, since 21 + 9 + 86 + 550 = 666.

It is a congruent number.

It is an unprimeable number.

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 17 ways as a sum of consecutive naturals, for example, 23980 + ... + 24879.

Almost surely, 2^21986550 is an apocalyptic number.

21986550 is an abundant number, since it is smaller than the sum of its proper divisors (37085190).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21986550 is a wasteful number, since it uses less digits than its factorization.

21986550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48877 (or 48869 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 21986550 is about 4688.9817657995. The cubic root of 21986550 is about 280.1468192597.

The spelling of 21986550 in words is "twenty-one million, nine hundred eighty-six thousand, five hundred fifty".