21003455305 has 48 divisors (see below), whose sum is σ = 29667980160. Its totient is φ = 14232008448.

The previous prime is 21003455267. The next prime is 21003455321. The reversal of 21003455305 is 50355430012.

It is not a de Polignac number, because 21003455305 - 2¹⁵ = 21003422537 is a prime.

It is a super-2 number, since 2×21003455305² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 7933492 + ... + 7936138.

It is an arithmetic number, because the mean of its divisors is an integer number (618082920).

Almost surely, 2^21003455305 is an apocalyptic number.

It is an amenable number.

21003455305 is a deficient number, since it is larger than the sum of its proper divisors (8664524855).

21003455305 is a wasteful number, since it uses less digits than its factorization.

21003455305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3038 (or 3031 counting only the distinct ones).

The product of its (nonzero) digits is 9000, while the sum is 28.

Adding to 21003455305 its reverse (50355430012), we get a palindrome (71358885317).

The spelling of 21003455305 in words is "twenty-one billion, three million, four hundred fifty-five thousand, three hundred five".