21838534 has 8 divisors (see below), whose sum is σ = 33206760. Its totient is φ = 10769616.

The previous prime is 21838519. The next prime is 21838561. The reversal of 21838534 is 43583812.

It is a happy number.

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 21838534.

It is a congruent number.

It is an unprimeable number.

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, 74644 + ... + 74935.

It is an arithmetic number, because the mean of its divisors is an integer number (4150845).

Almost surely, 2^21838534 is an apocalyptic number.

21838534 is a deficient number, since it is larger than the sum of its proper divisors (11368226).

21838534 is a wasteful number, since it uses less digits than its factorization.

21838534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149654.

The product of its digits is 23040, while the sum is 34.

The square root of 21838534 is about 4673.1717280665. The cubic root of 21838534 is about 279.5167429484.

The spelling of 21838534 in words is "twenty-one million, eight hundred thirty-eight thousand, five hundred thirty-four".