21604650 has 24 divisors (see below), whose sum is σ = 53579904. Its totient is φ = 5761200.

The previous prime is 21604643. The next prime is 21604669. The reversal of 21604650 is 5640612.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21604650.

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 in 11 ways as a sum of consecutive naturals, for example, 71866 + ... + 72165.

It is an arithmetic number, because the mean of its divisors is an integer number (2232496).

Almost surely, 2^21604650 is an apocalyptic number.

21604650 is an abundant number, since it is smaller than the sum of its proper divisors (31975254).

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

21604650 is a wasteful number, since it uses less digits than its factorization.

21604650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144046 (or 144041 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 21604650 is about 4648.0802488769. The cubic root of 21604650 is about 278.5153132014.

The spelling of 21604650 in words is "twenty-one million, six hundred four thousand, six hundred fifty".