21107019648 has 256 divisors, whose sum is σ = 66861930240. Its totient is φ = 5814927360.

The previous prime is 21107019643. The next prime is 21107019653. The reversal of 21107019648 is 84691070112.

It is an interprime number because it is at equal distance from previous prime (21107019643) and next prime (21107019653).

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21107019643) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3676236 + ... + 3681972.

It is an arithmetic number, because the mean of its divisors is an integer number (261179415).

Almost surely, 2^21107019648 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 21107019648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33430965120).

21107019648 is an abundant number, since it is smaller than the sum of its proper divisors (45754910592).

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

21107019648 is a wasteful number, since it uses less digits than its factorization.

21107019648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5845 (or 5833 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 39.

The spelling of 21107019648 in words is "twenty-one billion, one hundred seven million, nineteen thousand, six hundred forty-eight".