21013010505 has 24 divisors (see below), whose sum is σ = 36427764672. Its totient is φ = 11205334944.

The previous prime is 21013010503. The next prime is 21013010521. The reversal of 21013010505 is 50501031012.

21013010505 is a `hidden beast` number, since 21 + 0 + 130 + 10 + 505 = 666.

It is not a de Polignac number, because 21013010505 - 2¹ = 21013010503 is a prime.

It is a super-2 number, since 2×21013010505² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21013010503) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 327262 + ... + 386168.

It is an arithmetic number, because the mean of its divisors is an integer number (1517823528).

Almost surely, 2^21013010505 is an apocalyptic number.

It is an amenable number.

21013010505 is a deficient number, since it is larger than the sum of its proper divisors (15414754167).

21013010505 is a wasteful number, since it uses less digits than its factorization.

21013010505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66845 (or 66842 counting only the distinct ones).

The product of its (nonzero) digits is 150, while the sum is 18.

Adding to 21013010505 its reverse (50501031012), we get a palindrome (71514041517).

The spelling of 21013010505 in words is "twenty-one billion, thirteen million, ten thousand, five hundred five".