21002505405200 has 480 divisors, whose sum is σ = 56542706035200. Its totient is φ = 7432888320000.

The previous prime is 21002505405173. The next prime is 21002505405269. The reversal of 21002505405200 is 250450520012.

It is a super-2 number, since 2×21002505405200² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21002505405200.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 12405495554 + ... + 12405497246.

It is an arithmetic number, because the mean of its divisors is an integer number (117797304240).

Almost surely, 2^{21002505405200} is an apocalyptic number.

21002505405200 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 21002505405200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28271353017600).

21002505405200 is an abundant number, since it is smaller than the sum of its proper divisors (35540200630000).

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

21002505405200 is a wasteful number, since it uses less digits than its factorization.

21002505405200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2291 (or 2280 counting only the distinct ones).

The product of its (nonzero) digits is 4000, while the sum is 26.

Adding to 21002505405200 its reverse (250450520012), we get a palindrome (21252955925212).

The spelling of 21002505405200 in words is "twenty-one trillion, two billion, five hundred five million, four hundred five thousand, two hundred".