21916969 has 4 divisors (see below), whose sum is σ = 22624000. Its totient is φ = 21209940.

The previous prime is 21916967. The next prime is 21916981. The reversal of 21916969 is 96961912.

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 21916969 - 2¹ = 21916967 is a prime.

It is a super-2 number, since 2×21916969² = 960707060293922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21916967) 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 3 ways as a sum of consecutive naturals, for example, 353469 + ... + 353530.

It is an arithmetic number, because the mean of its divisors is an integer number (5656000).

Almost surely, 2^21916969 is an apocalyptic number.

It is an amenable number.

21916969 is a deficient number, since it is larger than the sum of its proper divisors (707031).

21916969 is an equidigital number, since it uses as much as digits as its factorization.

21916969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 707030.

The product of its digits is 52488, while the sum is 43.

The square root of 21916969 is about 4681.5562583397. The cubic root of 21916969 is about 279.8509793763.

The spelling of 21916969 in words is "twenty-one million, nine hundred sixteen thousand, nine hundred sixty-nine".