21822729 has 8 divisors (see below), whose sum is σ = 30035712. Its totient is φ = 14079120.

The previous prime is 21822727. The next prime is 21822733. The reversal of 21822729 is 92722812.

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

It is not a de Polignac number, because 21822729 - 2¹ = 21822727 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21822729.

It is not an unprimeable number, because it can be changed into a prime (21822721) 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, 117234 + ... + 117419.

It is an arithmetic number, because the mean of its divisors is an integer number (3754464).

Almost surely, 2^21822729 is an apocalyptic number.

It is an amenable number.

21822729 is a deficient number, since it is larger than the sum of its proper divisors (8212983).

21822729 is a wasteful number, since it uses less digits than its factorization.

21822729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234687.

The product of its digits is 8064, while the sum is 33.

The square root of 21822729 is about 4671.4803863444. The cubic root of 21822729 is about 279.4492959868.

The spelling of 21822729 in words is "twenty-one million, eight hundred twenty-two thousand, seven hundred twenty-nine".