21263818752 has 336 divisors, whose sum is σ = 67839774912. Its totient is φ = 6364200960.

The previous prime is 21263818649. The next prime is 21263818753. The reversal of 21263818752 is 25781836212.

21263818752 is a `hidden beast` number, since 2 + 1 + 2 + 638 + 1 + 8 + 7 + 5 + 2 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 21263818698 and 21263818707.

It is not an unprimeable number, because it can be changed into a prime (21263818753) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 127328173 + ... + 127328339.

It is an arithmetic number, because the mean of its divisors is an integer number (201904092).

Almost surely, 2^21263818752 is an apocalyptic number.

21263818752 is a gapful number since it is divisible by the number (22) 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 21263818752, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33919887456).

21263818752 is an abundant number, since it is smaller than the sum of its proper divisors (46575956160).

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

21263818752 is a wasteful number, since it uses less digits than its factorization.

21263818752 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 367 (or 340 counting only the distinct ones).

The product of its digits is 322560, while the sum is 45.

The spelling of 21263818752 in words is "twenty-one billion, two hundred sixty-three million, eight hundred eighteen thousand, seven hundred fifty-two".