21087201 has 8 divisors (see below), whose sum is σ = 28331424. Its totient is φ = 13950560.

The previous prime is 21087197. The next prime is 21087203. The reversal of 21087201 is 10278012.

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 21087201 - 2² = 21087197 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21087203) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 26436 + ... + 27221.

It is an arithmetic number, because the mean of its divisors is an integer number (3541428).

Almost surely, 2^21087201 is an apocalyptic number.

It is an amenable number.

21087201 is a deficient number, since it is larger than the sum of its proper divisors (7244223).

21087201 is a wasteful number, since it uses less digits than its factorization.

21087201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53791.

The product of its (nonzero) digits is 224, while the sum is 21.

The square root of 21087201 is about 4592.0802475567. The cubic root of 21087201 is about 276.2737648044.

The spelling of 21087201 in words is "twenty-one million, eighty-seven thousand, two hundred one".