21978479001600 has 2448 divisors, whose sum is σ = 92960837982720. Its totient is φ = 5046534144000.

The previous prime is 21978479001539. The next prime is 21978479001601. The reversal of 21978479001600 is 610097487912.

21978479001600 is a `hidden beast` number, since 2 + 1 + 9 + 7 + 8 + 479 + 0 + 0 + 160 + 0 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21978479001601) by changing a digit.

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 143 ways as a sum of consecutive naturals, for example, 467627212777 + ... + 467627212823.

Almost surely, 2^{21978479001600} is an apocalyptic number.

21978479001600 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 21978479001600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46480418991360).

21978479001600 is an abundant number, since it is smaller than the sum of its proper divisors (70982358981120).

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

21978479001600 is an equidigital number, since it uses as much as digits as its factorization.

21978479001600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171 (or 99 counting only the distinct ones).

The product of its (nonzero) digits is 1524096, while the sum is 54.

The spelling of 21978479001600 in words is "twenty-one trillion, nine hundred seventy-eight billion, four hundred seventy-nine million, one thousand, six hundred".