21003123255400 has 384 divisors, whose sum is σ = 58753977004800. Its totient is φ = 6881817600000.

The previous prime is 21003123255377. The next prime is 21003123255419. The reversal of 21003123255400 is 455232130012.

It is a super-2 number, since 2×21003123255400² (a number of 27 digits) contains 22 as substring.

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, 205039396 + ... + 205141804.

It is an arithmetic number, because the mean of its divisors is an integer number (153005148450).

Almost surely, 2^{21003123255400} is an apocalyptic number.

21003123255400 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 21003123255400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29376988502400).

21003123255400 is an abundant number, since it is smaller than the sum of its proper divisors (37750853749400).

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

21003123255400 is a wasteful number, since it uses less digits than its factorization.

21003123255400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102621 (or 102612 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 28.

Adding to 21003123255400 its reverse (455232130012), we get a palindrome (21458355385412).

The spelling of 21003123255400 in words is "twenty-one trillion, three billion, one hundred twenty-three million, two hundred fifty-five thousand, four hundred".