21153205122500 has 120 divisors (see below), whose sum is σ = 50578065088320. Its totient is φ = 7674548400000.

The previous prime is 21153205122451. The next prime is 21153205122503. The reversal of 21153205122500 is 522150235112.

It is a happy number.

21153205122500 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (21153205122503) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 11196410 + ... + 12948590.

It is an arithmetic number, because the mean of its divisors is an integer number (421483875736).

Almost surely, 2^{21153205122500} is an apocalyptic number.

21153205122500 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 21153205122500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25289032544160).

21153205122500 is an abundant number, since it is smaller than the sum of its proper divisors (29424859965820).

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

21153205122500 is a wasteful number, since it uses less digits than its factorization.

21153205122500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1752655 (or 1752638 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 29.

Adding to 21153205122500 its reverse (522150235112), we get a palindrome (21675355357612).

The spelling of 21153205122500 in words is "twenty-one trillion, one hundred fifty-three billion, two hundred five million, one hundred twenty-two thousand, five hundred".