21869101 has 2 divisors, whose sum is σ = 21869102. Its totient is φ = 21869100.

The previous prime is 21869093. The next prime is 21869119. The reversal of 21869101 is 10196812.

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., 21399876 + 469225 = 4626^2 + 685^2 .

It is a cyclic number.

It is not a de Polignac number, because 21869101 - 2³ = 21869093 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21869101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21869201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10934550 + 10934551.

It is an arithmetic number, because the mean of its divisors is an integer number (10934551).

Almost surely, 2^21869101 is an apocalyptic number.

It is an amenable number.

21869101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21869101 is an equidigital number, since it uses as much as digits as its factorization.

21869101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 28.

The square root of 21869101 is about 4676.4410613200. The cubic root of 21869101 is about 279.6470936561.

The spelling of 21869101 in words is "twenty-one million, eight hundred sixty-nine thousand, one hundred one".