21101308648 has 96 divisors (see below), whose sum is σ = 48928298400. Its totient is φ = 8482320000.

The previous prime is 21101308621. The next prime is 21101308649. The reversal of 21101308648 is 84680310112.

It is not an unprimeable number, because it can be changed into a prime (21101308649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 738223 + ... + 766273.

It is an arithmetic number, because the mean of its divisors is an integer number (509669775).

Almost surely, 2^21101308648 is an apocalyptic number.

21101308648 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21101308648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24464149200).

21101308648 is an abundant number, since it is smaller than the sum of its proper divisors (27826989752).

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

21101308648 is a wasteful number, since it uses less digits than its factorization.

21101308648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28191 (or 28180 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 34.

The spelling of 21101308648 in words is "twenty-one billion, one hundred one million, three hundred eight thousand, six hundred forty-eight".