21769369 has 4 divisors (see below), whose sum is σ = 21787920. Its totient is φ = 21750820.

The previous prime is 21769361. The next prime is 21769393. The reversal of 21769369 is 96396712.

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 21769369 - 2³ = 21769361 is a prime.

It is a super-2 number, since 2×21769369² = 947810853316322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21769361) 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, 7387 + ... + 9904.

It is an arithmetic number, because the mean of its divisors is an integer number (5446980).

Almost surely, 2^21769369 is an apocalyptic number.

It is an amenable number.

21769369 is a deficient number, since it is larger than the sum of its proper divisors (18551).

21769369 is a wasteful number, since it uses less digits than its factorization.

21769369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18550.

The product of its digits is 122472, while the sum is 43.

The square root of 21769369 is about 4665.7656392065. The cubic root of 21769369 is about 279.2213442863.

The spelling of 21769369 in words is "twenty-one million, seven hundred sixty-nine thousand, three hundred sixty-nine".