21985656215040 has 1280 divisors, whose sum is σ = 92592073728000. Its totient is φ = 4840319877120.

The previous prime is 21985656215027. The next prime is 21985656215059. The reversal of 21985656215040 is 4051265658912.

21985656215040 is a `hidden beast` number, since 2 + 1 + 9 + 8 + 5 + 6 + 5 + 621 + 5 + 0 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1280).

It is a hoax number, since the sum of its digits (54) 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 (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1567150746 + ... + 1567164774.

It is an arithmetic number, because the mean of its divisors is an integer number (72337557600).

Almost surely, 2^{21985656215040} is an apocalyptic number.

21985656215040 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 21985656215040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46296036864000).

21985656215040 is an abundant number, since it is smaller than the sum of its proper divisors (70606417512960).

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

21985656215040 is a wasteful number, since it uses less digits than its factorization.

21985656215040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14188 (or 14166 counting only the distinct ones).

The product of its (nonzero) digits is 5184000, while the sum is 54.

The spelling of 21985656215040 in words is "twenty-one trillion, nine hundred eighty-five billion, six hundred fifty-six million, two hundred fifteen thousand, forty".