21051034400000 has 216 divisors, whose sum is σ = 57296136125088. Its totient is φ = 7654918400000.

The previous prime is 21051034399951. The next prime is 21051034400003. The reversal of 21051034400000 is 443015012.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21051034400003) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7603919 + ... + 9996081.

It is an arithmetic number, because the mean of its divisors is an integer number (265259889468).

Almost surely, 2^{21051034400000} is an apocalyptic number.

21051034400000 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 21051034400000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28648068062544).

21051034400000 is an abundant number, since it is smaller than the sum of its proper divisors (36245101725088).

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

21051034400000 is an frugal number, since it uses more digits than its factorization.

21051034400000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2392215 (or 2392181 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

Adding to 21051034400000 its reverse (443015012), we get a palindrome (21051477415012).

The spelling of 21051034400000 in words is "twenty-one trillion, fifty-one billion, thirty-four million, four hundred thousand".