21769105 has 4 divisors (see below), whose sum is σ = 26122932. Its totient is φ = 17415280.

The previous prime is 21769103. The next prime is 21769123. The reversal of 21769105 is 50196712.

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

It can be written as a sum of positive squares in 2 ways, for example, as 13771521 + 7997584 = 3711^2 + 2828^2 .

It is not a de Polignac number, because 21769105 - 2¹ = 21769103 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21769103) 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 3 ways as a sum of consecutive naturals, for example, 2176906 + ... + 2176915.

It is an arithmetic number, because the mean of its divisors is an integer number (6530733).

Almost surely, 2^21769105 is an apocalyptic number.

It is an amenable number.

21769105 is a deficient number, since it is larger than the sum of its proper divisors (4353827).

21769105 is an equidigital number, since it uses as much as digits as its factorization.

21769105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4353826.

The product of its (nonzero) digits is 3780, while the sum is 31.

The square root of 21769105 is about 4665.7373479441. The cubic root of 21769105 is about 279.2202155638.

The spelling of 21769105 in words is "twenty-one million, seven hundred sixty-nine thousand, one hundred five".