21244774288536 has 320 divisors, whose sum is σ = 66027047486400. Its totient is φ = 6347864236032.

The previous prime is 21244774288511. The next prime is 21244774288589. The reversal of 21244774288536 is 63588247744212.

21244774288536 is a `hidden beast` number, since 2 + 1 + 2 + 4 + 4 + 7 + 74 + 28 + 8 + 536 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 58854810 + ... + 59214678.

It is an arithmetic number, because the mean of its divisors is an integer number (206334523395).

Almost surely, 2^{21244774288536} 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 21244774288536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33013523743200).

21244774288536 is an abundant number, since it is smaller than the sum of its proper divisors (44782273197864).

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

21244774288536 is a wasteful number, since it uses less digits than its factorization.

21244774288536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 360160 (or 360147 counting only the distinct ones).

The product of its digits is 144506880, while the sum is 63.

The spelling of 21244774288536 in words is "twenty-one trillion, two hundred forty-four billion, seven hundred seventy-four million, two hundred eighty-eight thousand, five hundred thirty-six".