21834009 has 16 divisors (see below), whose sum is σ = 32461440. Its totient is φ = 14504400.

The previous prime is 21833963. The next prime is 21834011. The reversal of 21834009 is 90043812.

It is not a de Polignac number, because 21834009 - 2¹⁷ = 21702937 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21834019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7284 + ... + 9834.

It is an arithmetic number, because the mean of its divisors is an integer number (2028840).

Almost surely, 2^21834009 is an apocalyptic number.

It is an amenable number.

21834009 is a deficient number, since it is larger than the sum of its proper divisors (10627431).

21834009 is a wasteful number, since it uses less digits than its factorization.

21834009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2877 (or 2871 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 21834009 is about 4672.6875564283. The cubic root of 21834009 is about 279.4974360873.

The spelling of 21834009 in words is "twenty-one million, eight hundred thirty-four thousand, nine".