21636850 has 12 divisors (see below), whose sum is σ = 40244634. Its totient is φ = 8654720.

The previous prime is 21636847. The next prime is 21636851. The reversal of 21636850 is 5863612.

It can be written as a sum of positive squares in 3 ways, for example, as 20638849 + 998001 = 4543^2 + 999^2 .

It is not an unprimeable number, because it can be changed into a prime (21636851) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 216319 + ... + 216418.

Almost surely, 2^21636850 is an apocalyptic number.

21636850 is a deficient number, since it is larger than the sum of its proper divisors (18607784).

21636850 is a wasteful number, since it uses less digits than its factorization.

21636850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432749 (or 432744 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 21636850 is about 4651.5427548288. The cubic root of 21636850 is about 278.6536127699.

The spelling of 21636850 in words is "twenty-one million, six hundred thirty-six thousand, eight hundred fifty".