21636201 has 8 divisors (see below), whose sum is σ = 28940544. Its totient is φ = 14378000.

The previous prime is 21636187. The next prime is 21636203. The reversal of 21636201 is 10263612.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21636201 - 2⁷ = 21636073 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21636203) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10425 + ... + 12326.

It is an arithmetic number, because the mean of its divisors is an integer number (3617568).

Almost surely, 2^21636201 is an apocalyptic number.

It is an amenable number.

21636201 is a deficient number, since it is larger than the sum of its proper divisors (7304343).

21636201 is a wasteful number, since it uses less digits than its factorization.

21636201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23071.

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 21636201 is about 4651.4729925046. The cubic root of 21636201 is about 278.6508266588.

Adding to 21636201 its reverse (10263612), we get a palindrome (31899813).

The spelling of 21636201 in words is "twenty-one million, six hundred thirty-six thousand, two hundred one".