21284101 has 4 divisors (see below), whose sum is σ = 21553600. Its totient is φ = 21014604.

The previous prime is 21284093. The next prime is 21284117. The reversal of 21284101 is 10148212.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21284101 - 2³ = 21284093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21284141) 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, 134631 + ... + 134788.

It is an arithmetic number, because the mean of its divisors is an integer number (5388400).

Almost surely, 2^21284101 is an apocalyptic number.

It is an amenable number.

21284101 is a deficient number, since it is larger than the sum of its proper divisors (269499).

21284101 is an equidigital number, since it uses as much as digits as its factorization.

21284101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 269498.

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 21284101 is about 4613.4695187028. The cubic root of 21284101 is about 277.1309967013.

The spelling of 21284101 in words is "twenty-one million, two hundred eighty-four thousand, one hundred one".