21823930 has 16 divisors (see below), whose sum is σ = 39336840. Its totient is φ = 8717632.

The previous prime is 21823897. The next prime is 21823981. The reversal of 21823930 is 3932812.

It can be written as a sum of positive squares in 4 ways, for example, as 15816529 + 6007401 = 3977^2 + 2451^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11916 + ... + 13624.

Almost surely, 2^21823930 is an apocalyptic number.

21823930 is a deficient number, since it is larger than the sum of its proper divisors (17512910).

21823930 is a wasteful number, since it uses less digits than its factorization.

21823930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2993.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 21823930 is about 4671.6089305506. The cubic root of 21823930 is about 279.4544223308.

The spelling of 21823930 in words is "twenty-one million, eight hundred twenty-three thousand, nine hundred thirty".