21533650 has 36 divisors (see below), whose sum is σ = 42307002. Its totient is φ = 8153280.

The previous prime is 21533647. The next prime is 21533683. The reversal of 21533650 is 5633512.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 16072081 + 5461569 = 4009^2 + 2337^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

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 17 ways as a sum of consecutive naturals, for example, 17454 + ... + 18646.

Almost surely, 2^21533650 is an apocalyptic number.

21533650 is a deficient number, since it is larger than the sum of its proper divisors (20773352).

21533650 is a wasteful number, since it uses less digits than its factorization.

21533650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1243 (or 1219 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 25.

The square root of 21533650 is about 4640.4364018915. The cubic root of 21533650 is about 278.2098806702.

The spelling of 21533650 in words is "twenty-one million, five hundred thirty-three thousand, six hundred fifty".