21192238 has 8 divisors (see below), whose sum is σ = 31813488. Its totient is φ = 10587744.

The previous prime is 21192233. The next prime is 21192247. The reversal of 21192238 is 83229112.

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

It is a super-2 number, since 2×21192238² = 898221902897288, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21192233) 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 3 ways as a sum of consecutive naturals, for example, 306 + ... + 6517.

It is an arithmetic number, because the mean of its divisors is an integer number (3976686).

Almost surely, 2^21192238 is an apocalyptic number.

21192238 is a deficient number, since it is larger than the sum of its proper divisors (10621250).

21192238 is a wasteful number, since it uses less digits than its factorization.

21192238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8378.

The product of its digits is 1728, while the sum is 28.

The square root of 21192238 is about 4603.5027967842. The cubic root of 21192238 is about 276.7317190300.

The spelling of 21192238 in words is "twenty-one million, one hundred ninety-two thousand, two hundred thirty-eight".