21830869 has 4 divisors (see below), whose sum is σ = 22129996. Its totient is φ = 21531744.

The previous prime is 21830843. The next prime is 21830891. The reversal of 21830869 is 96803812.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13593969 + 8236900 = 3687^2 + 2870^2 .

It is a cyclic number.

It is not a de Polignac number, because 21830869 - 2¹³ = 21822677 is a prime.

It is a super-2 number, since 2×21830869² = 953173682590322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21830269) 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, 149454 + ... + 149599.

It is an arithmetic number, because the mean of its divisors is an integer number (5532499).

Almost surely, 2^21830869 is an apocalyptic number.

It is an amenable number.

21830869 is a deficient number, since it is larger than the sum of its proper divisors (299127).

21830869 is an equidigital number, since it uses as much as digits as its factorization.

21830869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299126.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 21830869 is about 4672.3515492737. The cubic root of 21830869 is about 279.4840370512.

The spelling of 21830869 in words is "twenty-one million, eight hundred thirty thousand, eight hundred sixty-nine".