21518255543040 has 1080 divisors, whose sum is σ = 79717459808448. Its totient is φ = 5539792158720.

The previous prime is 21518255542963. The next prime is 21518255543063. The reversal of 21518255543040 is 4034555281512.

21518255543040 is a `hidden beast` number, since 2 + 1 + 5 + 1 + 8 + 25 + 554 + 30 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (1080).

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 119 ways as a sum of consecutive naturals, for example, 33569821120 + ... + 33569821760.

Almost surely, 2^{21518255543040} is an apocalyptic number.

21518255543040 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 21518255543040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39858729904224).

21518255543040 is an abundant number, since it is smaller than the sum of its proper divisors (58199204265408).

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

21518255543040 is an frugal number, since it uses more digits than its factorization.

21518255543040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 887 (or 781 counting only the distinct ones).

The product of its (nonzero) digits is 960000, while the sum is 45.

The spelling of 21518255543040 in words is "twenty-one trillion, five hundred eighteen billion, two hundred fifty-five million, five hundred forty-three thousand, forty".