21111212201000 has 32 divisors (see below), whose sum is σ = 49400236552680. Its totient is φ = 8444484880000.

The previous prime is 21111212200979. The next prime is 21111212201003. The reversal of 21111212201000 is 10221211112.

It can be written as a sum of positive squares in 4 ways, for example, as 10092782563396 + 11018429637604 = 3176914^2 + 3319402^2 .

It is not an unprimeable number, because it can be changed into a prime (21111212201003) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10555605101 + ... + 10555607100.

Almost surely, 2^{21111212201000} is an apocalyptic number.

21111212201000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21111212201000 is an abundant number, since it is smaller than the sum of its proper divisors (28289024351680).

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

21111212201000 is a wasteful number, since it uses less digits than its factorization.

21111212201000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21111212222 (or 21111212208 counting only the distinct ones).

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

Adding to 21111212201000 its reverse (10221211112), we get a palindrome (21121433412112).

The spelling of 21111212201000 in words is "twenty-one trillion, one hundred eleven billion, two hundred twelve million, two hundred one thousand".