21121001211200 has 168 divisors, whose sum is σ = 56704114749024. Its totient is φ = 7679195392000.

The previous prime is 21121001211187. The next prime is 21121001211217. The reversal of 21121001211200 is 211210012112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 120067310 + ... + 120243090.

Almost surely, 2^{21121001211200} is an apocalyptic number.

21121001211200 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 21121001211200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28352057374512).

21121001211200 is an abundant number, since it is smaller than the sum of its proper divisors (35583113537824).

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

21121001211200 is a wasteful number, since it uses less digits than its factorization.

21121001211200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182641 (or 182626 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21121001211200 its reverse (211210012112), we get a palindrome (21332211223312).

21121001211200 divided by its reverse (211210012112) gives a square (100 = 10²).

The spelling of 21121001211200 in words is "twenty-one trillion, one hundred twenty-one billion, one million, two hundred eleven thousand, two hundred".