21108220878240 has 864 divisors, whose sum is σ = 74927903057280. Its totient is φ = 5409317376000.

The previous prime is 21108220878233. The next prime is 21108220878281. The reversal of 21108220878240 is 4287802280112.

21108220878240 is a `hidden beast` number, since 2 + 1 + 108 + 220 + 87 + 8 + 240 = 666.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 139789542165 + ... + 139789542315.

It is an arithmetic number, because the mean of its divisors is an integer number (86722110020).

Almost surely, 2^{21108220878240} is an apocalyptic number.

21108220878240 is a gapful number since it is divisible by the number (20) 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 21108220878240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37463951528640).

21108220878240 is an abundant number, since it is smaller than the sum of its proper divisors (53819682179040).

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

21108220878240 is a wasteful number, since it uses less digits than its factorization.

21108220878240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 586 (or 468 counting only the distinct ones).

The product of its (nonzero) digits is 229376, while the sum is 45.

The spelling of 21108220878240 in words is "twenty-one trillion, one hundred eight billion, two hundred twenty million, eight hundred seventy-eight thousand, two hundred forty".