21986223 has 16 divisors (see below), whose sum is σ = 34584576. Its totient is φ = 12157920.

The previous prime is 21986221. The next prime is 21986227. The reversal of 21986223 is 32268912.

It is a happy number.

It is not a de Polignac number, because 21986223 - 2¹ = 21986221 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21986221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16236 + ... + 17537.

It is an arithmetic number, because the mean of its divisors is an integer number (2161536).

Almost surely, 2^21986223 is an apocalyptic number.

21986223 is a deficient number, since it is larger than the sum of its proper divisors (12598353).

21986223 is a wasteful number, since it uses less digits than its factorization.

21986223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33814.

The product of its digits is 10368, while the sum is 33.

The square root of 21986223 is about 4688.9468966923. The cubic root of 21986223 is about 280.1454304036.

The spelling of 21986223 in words is "twenty-one million, nine hundred eighty-six thousand, two hundred twenty-three".