21050523648 has 640 divisors, whose sum is σ = 79170474240. Its totient is φ = 5414584320.

The previous prime is 21050523631. The next prime is 21050523673. The reversal of 21050523648 is 84632505012.

21050523648 is a `hidden beast` number, since 2 + 1 + 0 + 5 + 0 + 5 + 2 + 3 + 648 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 204373965 + ... + 204374067.

It is an arithmetic number, because the mean of its divisors is an integer number (123703866).

Almost surely, 2^21050523648 is an apocalyptic number.

21050523648 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 21050523648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39585237120).

21050523648 is an abundant number, since it is smaller than the sum of its proper divisors (58119950592).

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

21050523648 is an equidigital number, since it uses as much as digits as its factorization.

21050523648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163 (or 126 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The spelling of 21050523648 in words is "twenty-one billion, fifty million, five hundred twenty-three thousand, six hundred forty-eight".