21755945955744 has 1728 divisors, whose sum is σ = 89450197095168. Its totient is φ = 4920304435200.

The previous prime is 21755945955703. The next prime is 21755945955773. The reversal of 21755945955744 is 44755954955712.

21755945955744 is a `hidden beast` number, since 2 + 1 + 7 + 5 + 5 + 9 + 45 + 9 + 5 + 574 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 3388245654 + ... + 3388252074.

It is an arithmetic number, because the mean of its divisors is an integer number (51765160356).

Almost surely, 2^{21755945955744} is an apocalyptic number.

21755945955744 is a gapful number since it is divisible by the number (24) 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 21755945955744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44725098547584).

21755945955744 is an abundant number, since it is smaller than the sum of its proper divisors (67694251139424).

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

21755945955744 is a wasteful number, since it uses less digits than its factorization.

21755945955744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6571 (or 6553 counting only the distinct ones).

The product of its digits is 1587600000, while the sum is 72.

The spelling of 21755945955744 in words is "twenty-one trillion, seven hundred fifty-five billion, nine hundred forty-five million, nine hundred fifty-five thousand, seven hundred forty-four".