21830357 has 4 divisors (see below), whose sum is σ = 22023660. Its totient is φ = 21637056.

The previous prime is 21830353. The next prime is 21830377. The reversal of 21830357 is 75303812.

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 1164241 + 20666116 = 1079^2 + 4546^2 .

It is a cyclic number.

It is not a de Polignac number, because 21830357 - 2² = 21830353 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21830353) 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, 96482 + ... + 96707.

It is an arithmetic number, because the mean of its divisors is an integer number (5505915).

Almost surely, 2^21830357 is an apocalyptic number.

It is an amenable number.

21830357 is a deficient number, since it is larger than the sum of its proper divisors (193303).

21830357 is a wasteful number, since it uses less digits than its factorization.

21830357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193302.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 21830357 is about 4672.2967585546. The cubic root of 21830357 is about 279.4818521184.

The spelling of 21830357 in words is "twenty-one million, eight hundred thirty thousand, three hundred fifty-seven".