21828101 has 2 divisors, whose sum is σ = 21828102. Its totient is φ = 21828100.

The previous prime is 21828083. The next prime is 21828151. The reversal of 21828101 is 10182812.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20205025 + 1623076 = 4495^2 + 1274^2 .

It is a cyclic number.

It is not a de Polignac number, because 21828101 - 2¹⁴ = 21811717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21828151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10914050 + 10914051.

It is an arithmetic number, because the mean of its divisors is an integer number (10914051).

Almost surely, 2^21828101 is an apocalyptic number.

It is an amenable number.

21828101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21828101 is an equidigital number, since it uses as much as digits as its factorization.

21828101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 256, while the sum is 23.

The square root of 21828101 is about 4672.0553292957. The cubic root of 21828101 is about 279.4722243513.

The spelling of 21828101 in words is "twenty-one million, eight hundred twenty-eight thousand, one hundred one".