21115026016 has 96 divisors (see below), whose sum is σ = 47968200000. Its totient is φ = 8962179072.

The previous prime is 21115026013. The next prime is 21115026019. The reversal of 21115026016 is 61062051112.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21115026013) and next prime (21115026019).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21115026013) 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 15 ways as a sum of consecutive naturals, for example, 14985120 + ... + 14986528.

It is an arithmetic number, because the mean of its divisors is an integer number (499668750).

Almost surely, 2^21115026016 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21115026016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23984100000).

21115026016 is an abundant number, since it is smaller than the sum of its proper divisors (26853173984).

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

21115026016 is a wasteful number, since it uses less digits than its factorization.

21115026016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2024 (or 2016 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 25.

Adding to 21115026016 its reverse (61062051112), we get a palindrome (82177077128).

The spelling of 21115026016 in words is "twenty-one billion, one hundred fifteen million, twenty-six thousand, sixteen".