21115530216510 has 64 divisors (see below), whose sum is σ = 51959534296320. Its totient is φ = 5488579134720.

The previous prime is 21115530216479. The next prime is 21115530216523. The reversal of 21115530216510 is 1561203551112.

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 (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6262120 + ... + 9024699.

It is an arithmetic number, because the mean of its divisors is an integer number (811867723380).

Almost surely, 2^{21115530216510} is an apocalyptic number.

21115530216510 is an abundant number, since it is smaller than the sum of its proper divisors (30844004079810).

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

21115530216510 is a wasteful number, since it uses less digits than its factorization.

21115530216510 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15287993.

The product of its (nonzero) digits is 9000, while the sum is 33.

Adding to 21115530216510 its reverse (1561203551112), we get a palindrome (22676733767622).

The spelling of 21115530216510 in words is "twenty-one trillion, one hundred fifteen billion, five hundred thirty million, two hundred sixteen thousand, five hundred ten".