21927198 has 16 divisors (see below), whose sum is σ = 44243856. Its totient is φ = 7244160.

The previous prime is 21927193. The next prime is 21927221. The reversal of 21927198 is 89172912.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21927193) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15493 + ... + 16848.

It is an arithmetic number, because the mean of its divisors is an integer number (2765241).

Almost surely, 2^21927198 is an apocalyptic number.

21927198 is an abundant number, since it is smaller than the sum of its proper divisors (22316658).

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

21927198 is a wasteful number, since it uses less digits than its factorization.

21927198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32459.

The product of its digits is 18144, while the sum is 39.

The square root of 21927198 is about 4682.6486094944. The cubic root of 21927198 is about 279.8945095810.

The spelling of 21927198 in words is "twenty-one million, nine hundred twenty-seven thousand, one hundred ninety-eight".