21053869056 has 352 divisors, whose sum is σ = 69895388160. Its totient is φ = 6204211200.

The previous prime is 21053869037. The next prime is 21053869061. The reversal of 21053869056 is 65096835012.

21053869056 is a `hidden beast` number, since 2 + 1 + 0 + 538 + 69 + 0 + 56 = 666.

It is a tau number, because it is divible by the number of its divisors (352).

It is a super-2 number, since 2×21053869056² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11251801 + ... + 11253671.

Almost surely, 2^21053869056 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 21053869056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34947694080).

21053869056 is an abundant number, since it is smaller than the sum of its proper divisors (48841519104).

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

21053869056 is a wasteful number, since it uses less digits than its factorization.

21053869056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1948 (or 1924 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The spelling of 21053869056 in words is "twenty-one billion, fifty-three million, eight hundred sixty-nine thousand, fifty-six".