21605163330 has 64 divisors (see below), whose sum is σ = 52115374080. Its totient is φ = 5732216256.

The previous prime is 21605163313. The next prime is 21605163373. The reversal of 21605163330 is 3336150612.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9648351 + ... + 9650589.

It is an arithmetic number, because the mean of its divisors is an integer number (814302720).

Almost surely, 2^21605163330 is an apocalyptic number.

21605163330 is an abundant number, since it is smaller than the sum of its proper divisors (30510210750).

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

21605163330 is a wasteful number, since it uses less digits than its factorization.

21605163330 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3735.

The product of its (nonzero) digits is 9720, while the sum is 30.

The spelling of 21605163330 in words is "twenty-one billion, six hundred five million, one hundred sixty-three thousand, three hundred thirty".