21968769 has 8 divisors (see below), whose sum is σ = 30833440. Its totient is φ = 13874976.

The previous prime is 21968761. The next prime is 21968773. The reversal of 21968769 is 96786912.

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

It is not a de Polignac number, because 21968769 - 2³ = 21968761 is a prime.

It is a super-2 number, since 2×21968769² = 965253622750722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21968761) 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, 192652 + ... + 192765.

It is an arithmetic number, because the mean of its divisors is an integer number (3854180).

Almost surely, 2^21968769 is an apocalyptic number.

It is an amenable number.

21968769 is a deficient number, since it is larger than the sum of its proper divisors (8864671).

21968769 is a wasteful number, since it uses less digits than its factorization.

21968769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 385439.

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

The square root of 21968769 is about 4687.0853416596. The cubic root of 21968769 is about 280.0712786220.

The spelling of 21968769 in words is "twenty-one million, nine hundred sixty-eight thousand, seven hundred sixty-nine".