21824290 has 8 divisors (see below), whose sum is σ = 39283740. Its totient is φ = 8729712.

The previous prime is 21824261. The next prime is 21824291. The reversal of 21824290 is 9242812.

It can be written as a sum of positive squares in 2 ways, for example, as 19900521 + 1923769 = 4461^2 + 1387^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21824291) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1091205 + ... + 1091224.

Almost surely, 2^21824290 is an apocalyptic number.

21824290 is a deficient number, since it is larger than the sum of its proper divisors (17459450).

21824290 is a wasteful number, since it uses less digits than its factorization.

21824290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2182436.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 21824290 is about 4671.6474610142. The cubic root of 21824290 is about 279.4559589168.

The spelling of 21824290 in words is "twenty-one million, eight hundred twenty-four thousand, two hundred ninety".