21769385 has 16 divisors (see below), whose sum is σ = 29738880. Its totient is φ = 15143040.

The previous prime is 21769361. The next prime is 21769393. The reversal of 21769385 is 58396712.

It is not a de Polignac number, because 21769385 - 2¹⁰ = 21768361 is a prime.

It is a super-2 number, since 2×21769385² = 947812246556450, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 7340 + ... + 9869.

It is an arithmetic number, because the mean of its divisors is an integer number (1858680).

Almost surely, 2^21769385 is an apocalyptic number.

It is an amenable number.

21769385 is a deficient number, since it is larger than the sum of its proper divisors (7969495).

21769385 is a wasteful number, since it uses less digits than its factorization.

21769385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17248.

The product of its digits is 90720, while the sum is 41.

The square root of 21769385 is about 4665.7673538229. The cubic root of 21769385 is about 279.2214126934.

The spelling of 21769385 in words is "twenty-one million, seven hundred sixty-nine thousand, three hundred eighty-five".