21217475523400 has 192 divisors, whose sum is σ = 55788204326400. Its totient is φ = 7445797032960.

The previous prime is 21217475523373. The next prime is 21217475523403. The reversal of 21217475523400 is 432557471212.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21217475523403) 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 47 ways as a sum of consecutive naturals, for example, 8258641 + ... + 10518559.

It is an arithmetic number, because the mean of its divisors is an integer number (290563564200).

Almost surely, 2^{21217475523400} is an apocalyptic number.

21217475523400 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 21217475523400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27894102163200).

21217475523400 is an abundant number, since it is smaller than the sum of its proper divisors (34570728803000).

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

21217475523400 is a wasteful number, since it uses less digits than its factorization.

21217475523400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2260128 (or 2260119 counting only the distinct ones).

The product of its (nonzero) digits is 470400, while the sum is 43.

The spelling of 21217475523400 in words is "twenty-one trillion, two hundred seventeen billion, four hundred seventy-five million, five hundred twenty-three thousand, four hundred".