21045030066 has 56 divisors (see below), whose sum is σ = 47670626640. Its totient is φ = 6964475256.

The previous prime is 21045030049. The next prime is 21045030101. The reversal of 21045030066 is 66003054012.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 150741 + ... + 254583.

It is an arithmetic number, because the mean of its divisors is an integer number (851261190).

Almost surely, 2^21045030066 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21045030066, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23835313320).

21045030066 is an abundant number, since it is smaller than the sum of its proper divisors (26625596574).

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

21045030066 is a wasteful number, since it uses less digits than its factorization.

21045030066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104002 (or 103987 counting only the distinct ones).

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

Adding to 21045030066 its reverse (66003054012), we get a palindrome (87048084078).

The spelling of 21045030066 in words is "twenty-one billion, forty-five million, thirty thousand, sixty-six".