21454317478944 has 720 divisors, whose sum is σ = 81094685874048. Its totient is φ = 5518379446272.

The previous prime is 21454317478903. The next prime is 21454317478973. The reversal of 21454317478944 is 44987471345412.

21454317478944 is a `hidden beast` number, since 2 + 1 + 4 + 543 + 1 + 7 + 4 + 7 + 89 + 4 + 4 = 666.

It is a Smith number, since the sum of its digits (63) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 49444117 + ... + 49876139.

Almost surely, 2^{21454317478944} is an apocalyptic number.

21454317478944 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 21454317478944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40547342937024).

21454317478944 is an abundant number, since it is smaller than the sum of its proper divisors (59640368395104).

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

21454317478944 is a wasteful number, since it uses less digits than its factorization.

21454317478944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432099 (or 432075 counting only the distinct ones).

The product of its digits is 108380160, while the sum is 63.

The spelling of 21454317478944 in words is "twenty-one trillion, four hundred fifty-four billion, three hundred seventeen million, four hundred seventy-eight thousand, nine hundred forty-four".