21154304 has 40 divisors (see below), whose sum is σ = 42884160. Its totient is φ = 10423296.

The previous prime is 21154283. The next prime is 21154339. The reversal of 21154304 is 40345112.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40187 + ... + 40709.

It is an arithmetic number, because the mean of its divisors is an integer number (1072104).

Almost surely, 2^21154304 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21154304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21442080).

21154304 is an abundant number, since it is smaller than the sum of its proper divisors (21729856).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21154304 is an frugal number, since it uses more digits than its factorization.

21154304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 620 (or 604 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 21154304 is about 4599.3808278941. The cubic root of 21154304 is about 276.5665042820.

Adding to 21154304 its reverse (40345112), we get a palindrome (61499416).

The spelling of 21154304 in words is "twenty-one million, one hundred fifty-four thousand, three hundred four".