21288798732492 has 144 divisors (see below), whose sum is σ = 55667065420512. Its totient is φ = 6854666757120.

The previous prime is 21288798732491. The next prime is 21288798732521. The reversal of 21288798732492 is 29423789788212.

21288798732492 is a `hidden beast` number, since 2 + 1 + 28 + 8 + 7 + 9 + 87 + 32 + 492 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21288798732492.

It is not an unprimeable number, because it can be changed into a prime (21288798732491) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 249442267 + ... + 249527597.

It is an arithmetic number, because the mean of its divisors is an integer number (386576843198).

Almost surely, 2^{21288798732492} 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 21288798732492, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27833532710256).

21288798732492 is an abundant number, since it is smaller than the sum of its proper divisors (34378266688020).

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

21288798732492 is a wasteful number, since it uses less digits than its factorization.

21288798732492 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86728 (or 86723 counting only the distinct ones).

The product of its digits is 390168576, while the sum is 72.

The spelling of 21288798732492 in words is "twenty-one trillion, two hundred eighty-eight billion, seven hundred ninety-eight million, seven hundred thirty-two thousand, four hundred ninety-two".