21455014318920 has 768 divisors, whose sum is σ = 91498725964800. Its totient is φ = 4430451271680.

The previous prime is 21455014318877. The next prime is 21455014318981. The reversal of 21455014318920 is 2981341055412.

21455014318920 is a `hidden beast` number, since 2 + 1 + 4 + 5 + 501 + 43 + 1 + 89 + 20 = 666.

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 191 ways as a sum of consecutive naturals, for example, 32002350 + ... + 32665890.

It is an arithmetic number, because the mean of its divisors is an integer number (119138966100).

Almost surely, 2^{21455014318920} is an apocalyptic number.

21455014318920 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 21455014318920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45749362982400).

21455014318920 is an abundant number, since it is smaller than the sum of its proper divisors (70043711645880).

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

21455014318920 is a wasteful number, since it uses less digits than its factorization.

21455014318920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 663635 (or 663618 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 45.

The spelling of 21455014318920 in words is "twenty-one trillion, four hundred fifty-five billion, fourteen million, three hundred eighteen thousand, nine hundred twenty".