21165204330 has 24 divisors (see below), whose sum is σ = 55029531492. Its totient is φ = 5644054464.

The previous prime is 21165204329. The next prime is 21165204331. The reversal of 21165204330 is 3340256112.

21165204330 is a `hidden beast` number, since 2 + 1 + 1 + 652 + 0 + 4 + 3 + 3 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (21165204329) and next prime (21165204331).

It can be written as a sum of positive squares in 2 ways, for example, as 20373851169 + 791353161 = 142737^2 + 28131^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21165204294 and 21165204303.

It is not an unprimeable number, because it can be changed into a prime (21165204331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 117584379 + ... + 117584558.

Almost surely, 2^21165204330 is an apocalyptic number.

21165204330 is an abundant number, since it is smaller than the sum of its proper divisors (33864327162).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21165204330 is a wasteful number, since it uses less digits than its factorization.

21165204330 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235168950 (or 235168947 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The spelling of 21165204330 in words is "twenty-one billion, one hundred sixty-five million, two hundred four thousand, three hundred thirty".