21121948403568 has 120 divisors (see below), whose sum is σ = 59671194794640. Its totient is φ = 6974096163840.

The previous prime is 21121948403527. The next prime is 21121948403659. The reversal of 21121948403568 is 86530484912112.

21121948403568 is a `hidden beast` number, since 2 + 1 + 121 + 9 + 484 + 0 + 35 + 6 + 8 = 666.

It is a super-2 number, since 2×21121948403568² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 56208463 + ... + 56582993.

It is an arithmetic number, because the mean of its divisors is an integer number (497259956622).

Almost surely, 2^{21121948403568} 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 21121948403568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29835597397320).

21121948403568 is an abundant number, since it is smaller than the sum of its proper divisors (38549246391072).

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

21121948403568 is a wasteful number, since it uses less digits than its factorization.

21121948403568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 378247 (or 378238 counting only the distinct ones).

The product of its (nonzero) digits is 3317760, while the sum is 54.

The spelling of 21121948403568 in words is "twenty-one trillion, one hundred twenty-one billion, nine hundred forty-eight million, four hundred three thousand, five hundred sixty-eight".