21804298 has 4 divisors (see below), whose sum is σ = 32706450. Its totient is φ = 10902148.

The previous prime is 21804283. The next prime is 21804329. The reversal of 21804298 is 89240812.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 21780889 + 23409 = 4667^2 + 153^2 .

It is a super-3 number, since 3×21804298³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 5451073 + ... + 5451076.

Almost surely, 2^21804298 is an apocalyptic number.

21804298 is a deficient number, since it is larger than the sum of its proper divisors (10902152).

21804298 is a wasteful number, since it uses less digits than its factorization.

21804298 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10902151.

The product of its (nonzero) digits is 9216, while the sum is 34.

The square root of 21804298 is about 4669.5072545184. The cubic root of 21804298 is about 279.3706015720.

The spelling of 21804298 in words is "twenty-one million, eight hundred four thousand, two hundred ninety-eight".