21154834 has 16 divisors (see below), whose sum is σ = 34684416. Its totient is φ = 9633600.

The previous prime is 21154831. The next prime is 21154849. The reversal of 21154834 is 43845112.

It is not an unprimeable number, because it can be changed into a prime (21154831) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8982 + ... + 11089.

It is an arithmetic number, because the mean of its divisors is an integer number (2167776).

Almost surely, 2^21154834 is an apocalyptic number.

21154834 is a deficient number, since it is larger than the sum of its proper divisors (13529582).

21154834 is a wasteful number, since it uses less digits than its factorization.

21154834 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20121.

The product of its digits is 3840, while the sum is 28.

The square root of 21154834 is about 4599.4384439842. The cubic root of 21154834 is about 276.5688139621.

Adding to 21154834 its reverse (43845112), we get a palindrome (64999946).

The spelling of 21154834 in words is "twenty-one million, one hundred fifty-four thousand, eight hundred thirty-four".