21078541449504 has 2016 divisors, whose sum is σ = 86325573422592. Its totient is φ = 4985100288000.

The previous prime is 21078541449461. The next prime is 21078541449517. The reversal of 21078541449504 is 40594414587012.

21078541449504 is a `hidden beast` number, since 2 + 1 + 0 + 7 + 8 + 541 + 4 + 4 + 95 + 0 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (2016).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 335 ways as a sum of consecutive naturals, for example, 6626386794 + ... + 6626389974.

It is an arithmetic number, because the mean of its divisors is an integer number (42820224912).

Almost surely, 2^{21078541449504} is an apocalyptic number.

21078541449504 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 21078541449504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43162786711296).

21078541449504 is an abundant number, since it is smaller than the sum of its proper divisors (65247031973088).

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

21078541449504 is a wasteful number, since it uses less digits than its factorization.

21078541449504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3282 (or 3252 counting only the distinct ones).

The product of its (nonzero) digits is 6451200, while the sum is 54.

The spelling of 21078541449504 in words is "twenty-one trillion, seventy-eight billion, five hundred forty-one million, four hundred forty-nine thousand, five hundred four".