21817342 has 8 divisors (see below), whose sum is σ = 32747976. Its totient is φ = 10901352.

The previous prime is 21817333. The next prime is 21817349. The reversal of 21817342 is 24371812.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21817342.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21817349) 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 3 ways as a sum of consecutive naturals, for example, 1548 + ... + 6784.

It is an arithmetic number, because the mean of its divisors is an integer number (4093497).

Almost surely, 2^21817342 is an apocalyptic number.

21817342 is a deficient number, since it is larger than the sum of its proper divisors (10930634).

21817342 is a wasteful number, since it uses less digits than its factorization.

21817342 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7322.

The product of its digits is 2688, while the sum is 28.

The square root of 21817342 is about 4670.9037669385. The cubic root of 21817342 is about 279.4262998216.

The spelling of 21817342 in words is "twenty-one million, eight hundred seventeen thousand, three hundred forty-two".