21769689 has 8 divisors (see below), whose sum is σ = 29120832. Its totient is φ = 14465840.

The previous prime is 21769681. The next prime is 21769717. The reversal of 21769689 is 98696712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21769689 - 2³ = 21769681 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21769681) 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 in 7 ways as a sum of consecutive naturals, for example, 10734 + ... + 12599.

It is an arithmetic number, because the mean of its divisors is an integer number (3640104).

Almost surely, 2^21769689 is an apocalyptic number.

It is an amenable number.

21769689 is a deficient number, since it is larger than the sum of its proper divisors (7351143).

21769689 is a wasteful number, since it uses less digits than its factorization.

21769689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23647.

The product of its digits is 326592, while the sum is 48.

The square root of 21769689 is about 4665.7999314158. The cubic root of 21769689 is about 279.2227124226. Note that the first 3 decimals are identical.

The spelling of 21769689 in words is "twenty-one million, seven hundred sixty-nine thousand, six hundred eighty-nine".