21102127 has 4 divisors (see below), whose sum is σ = 21130200. Its totient is φ = 21074056.

The previous prime is 21102113. The next prime is 21102161. The reversal of 21102127 is 72120112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21102127 - 2¹⁵ = 21069359 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21102127.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102187) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12877 + ... + 14422.

It is an arithmetic number, because the mean of its divisors is an integer number (5282550).

Almost surely, 2^21102127 is an apocalyptic number.

21102127 is a deficient number, since it is larger than the sum of its proper divisors (28073).

21102127 is an equidigital number, since it uses as much as digits as its factorization.

21102127 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28072.

The product of its (nonzero) digits is 56, while the sum is 16.

The square root of 21102127 is about 4593.7051494409. The cubic root of 21102127 is about 276.3389337135.

Adding to 21102127 its reverse (72120112), we get a palindrome (93222239).

The spelling of 21102127 in words is "twenty-one million, one hundred two thousand, one hundred twenty-seven".