21042451055500 has 192 divisors, whose sum is σ = 52886549753856. Its totient is φ = 7164504000000.

The previous prime is 21042451055389. The next prime is 21042451055501. The reversal of 21042451055500 is 555015424012.

It is a super-2 number, since 2×21042451055500² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21042451055501) 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 63 ways as a sum of consecutive naturals, for example, 3250800264 + ... + 3250806736.

It is an arithmetic number, because the mean of its divisors is an integer number (275450779968).

Almost surely, 2^{21042451055500} is an apocalyptic number.

21042451055500 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 21042451055500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26443274876928).

21042451055500 is an abundant number, since it is smaller than the sum of its proper divisors (31844098698356).

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

21042451055500 is a wasteful number, since it uses less digits than its factorization.

21042451055500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12801 (or 12789 counting only the distinct ones).

The product of its (nonzero) digits is 40000, while the sum is 34.

Adding to 21042451055500 its reverse (555015424012), we get a palindrome (21597466479512).

The spelling of 21042451055500 in words is "twenty-one trillion, forty-two billion, four hundred fifty-one million, fifty-five thousand, five hundred".