21973569 has 8 divisors (see below), whose sum is σ = 29319840. Its totient is φ = 14638176.

The previous prime is 21973529. The next prime is 21973591. The reversal of 21973569 is 96537912.

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

It is not a de Polignac number, because 21973569 - 2¹⁷ = 21842497 is a prime.

It is a super-2 number, since 2×21973569² = 965675469195522, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21973569.

It is not an unprimeable number, because it can be changed into a prime (21973529) 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 7 ways as a sum of consecutive naturals, for example, 5917 + ... + 8885.

It is an arithmetic number, because the mean of its divisors is an integer number (3664980).

Almost surely, 2^21973569 is an apocalyptic number.

It is an amenable number.

21973569 is a deficient number, since it is larger than the sum of its proper divisors (7346271).

21973569 is a wasteful number, since it uses less digits than its factorization.

21973569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5439.

The product of its digits is 102060, while the sum is 42.

The square root of 21973569 is about 4687.5973589889. The cubic root of 21973569 is about 280.0916749134.

The spelling of 21973569 in words is "twenty-one million, nine hundred seventy-three thousand, five hundred sixty-nine".