21006006510 has 64 divisors (see below), whose sum is σ = 53206917120. Its totient is φ = 5292869760.

The previous prime is 21006006509. The next prime is 21006006547. The reversal of 21006006510 is 1560060012.

It is a happy number.

It is a congruent number.

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 31 ways as a sum of consecutive naturals, for example, 170200 + ... + 266420.

It is an arithmetic number, because the mean of its divisors is an integer number (831358080).

Almost surely, 2^21006006510 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21006006510, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26603458560).

21006006510 is an abundant number, since it is smaller than the sum of its proper divisors (32200910610).

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

21006006510 is a wasteful number, since it uses less digits than its factorization.

21006006510 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96633.

The product of its (nonzero) digits is 360, while the sum is 21.

Adding to 21006006510 its reverse (1560060012), we get a palindrome (22566066522).

The spelling of 21006006510 in words is "twenty-one billion, six million, six thousand, five hundred ten".