21810230 has 16 divisors (see below), whose sum is σ = 42278544. Its totient is φ = 8052960.

The previous prime is 21810221. The next prime is 21810253. The reversal of 21810230 is 3201812.

It is a super-2 number, since 2×21810230² = 951372265305800, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21810199 and 21810208.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83756 + ... + 84015.

It is an arithmetic number, because the mean of its divisors is an integer number (2642409).

Almost surely, 2^21810230 is an apocalyptic number.

21810230 is a deficient number, since it is larger than the sum of its proper divisors (20468314).

21810230 is a wasteful number, since it uses less digits than its factorization.

21810230 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167791.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 21810230 is about 4670.1423961160. The cubic root of 21810230 is about 279.3959341333.

The spelling of 21810230 in words is "twenty-one million, eight hundred ten thousand, two hundred thirty".