21723069 has 8 divisors (see below), whose sum is σ = 29030400. Its totient is φ = 14448896.

The previous prime is 21723067. The next prime is 21723073. The reversal of 21723069 is 96032712.

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 21723069 - 2¹ = 21723067 is a prime.

It is a super-2 number, since 2×21723069² = 943783453557522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21723067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6717 + ... + 9410.

It is an arithmetic number, because the mean of its divisors is an integer number (3628800).

Almost surely, 2^21723069 is an apocalyptic number.

It is an amenable number.

21723069 is a deficient number, since it is larger than the sum of its proper divisors (7307331).

21723069 is a wasteful number, since it uses less digits than its factorization.

21723069 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16579.

The product of its (nonzero) digits is 4536, while the sum is 30.

The square root of 21723069 is about 4660.8013259524. The cubic root of 21723069 is about 279.0232505899.

The spelling of 21723069 in words is "twenty-one million, seven hundred twenty-three thousand, sixty-nine".