21812330 has 8 divisors (see below), whose sum is σ = 39262212. Its totient is φ = 8724928.

The previous prime is 21812279. The next prime is 21812353. The reversal of 21812330 is 3321812.

It can be written as a sum of positive squares in 2 ways, for example, as 21799561 + 12769 = 4669^2 + 113^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1090607 + ... + 1090626.

Almost surely, 2^21812330 is an apocalyptic number.

21812330 is a deficient number, since it is larger than the sum of its proper divisors (17449882).

21812330 is a wasteful number, since it uses less digits than its factorization.

21812330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2181240.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 21812330 is about 4670.3672232492. The cubic root of 21812330 is about 279.4049010665.

The spelling of 21812330 in words is "twenty-one million, eight hundred twelve thousand, three hundred thirty".