21604298 has 4 divisors (see below), whose sum is σ = 32406450. Its totient is φ = 10802148.

The previous prime is 21604267. The next prime is 21604301. The reversal of 21604298 is 89240612.

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., 11950849 + 9653449 = 3457^2 + 3107^2 .

It is a Curzon 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 as a sum of consecutive naturals, namely, 5401073 + ... + 5401076.

Almost surely, 2^21604298 is an apocalyptic number.

21604298 is a deficient number, since it is larger than the sum of its proper divisors (10802152).

21604298 is a wasteful number, since it uses less digits than its factorization.

21604298 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10802151.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 21604298 is about 4648.0423836278. The cubic root of 21604298 is about 278.5138005962.

The spelling of 21604298 in words is "twenty-one million, six hundred four thousand, two hundred ninety-eight".