21179985297408 has 960 divisors, whose sum is σ = 74510698822560. Its totient is φ = 5870683422720.

The previous prime is 21179985297407. The next prime is 21179985297433. The reversal of 21179985297408 is 80479258997112.

21179985297408 is a `hidden beast` number, since 2 + 1 + 1 + 7 + 9 + 98 + 529 + 7 + 4 + 0 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21179985297403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 290136784860 + ... + 290136784932.

Almost surely, 2^{21179985297408} is an apocalyptic number.

21179985297408 is a gapful number since it is divisible by the number (28) 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 21179985297408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37255349411280).

21179985297408 is an abundant number, since it is smaller than the sum of its proper divisors (53330713525152).

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

21179985297408 is an frugal number, since it uses more digits than its factorization.

21179985297408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199 (or 146 counting only the distinct ones).

The product of its (nonzero) digits is 182891520, while the sum is 72.

The spelling of 21179985297408 in words is "twenty-one trillion, one hundred seventy-nine billion, nine hundred eighty-five million, two hundred ninety-seven thousand, four hundred eight".