21006210511 has 8 divisors (see below), whose sum is σ = 24678625104. Its totient is φ = 17627589120.

The previous prime is 21006210499. The next prime is 21006210539. The reversal of 21006210511 is 11501260012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21006210511 - 2¹⁹ = 21005686223 is a prime.

It is a super-2 number, since 2×21006210511² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21006210541) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 73448146 + ... + 73448431.

It is an arithmetic number, because the mean of its divisors is an integer number (3084828138).

Almost surely, 2^21006210511 is an apocalyptic number.

21006210511 is a deficient number, since it is larger than the sum of its proper divisors (3672414593).

21006210511 is a wasteful number, since it uses less digits than its factorization.

21006210511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146896601.

The product of its (nonzero) digits is 120, while the sum is 19.

Adding to 21006210511 its reverse (11501260012), we get a palindrome (32507470523).

The spelling of 21006210511 in words is "twenty-one billion, six million, two hundred ten thousand, five hundred eleven".