21189201 has 16 divisors (see below), whose sum is σ = 31345920. Its totient is φ = 12623120.

The previous prime is 21189173. The next prime is 21189221. The reversal of 21189201 is 10298112.

It is a cyclic number.

It is not a de Polignac number, because 21189201 - 2¹⁷ = 21058129 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21189221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3495 + ... + 7388.

It is an arithmetic number, because the mean of its divisors is an integer number (1959120).

Almost surely, 2^21189201 is an apocalyptic number.

It is an amenable number.

21189201 is a deficient number, since it is larger than the sum of its proper divisors (10156719).

21189201 is a wasteful number, since it uses less digits than its factorization.

21189201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10956.

The product of its (nonzero) digits is 288, while the sum is 24.

The square root of 21189201 is about 4603.1729274491. The cubic root of 21189201 is about 276.7184991838.

The spelling of 21189201 in words is "twenty-one million, one hundred eighty-nine thousand, two hundred one".