21011111001200 has 120 divisors (see below), whose sum is σ = 51867467497296. Its totient is φ = 8174928384000.

The previous prime is 21011111001149. The next prime is 21011111001253. The reversal of 21011111001200 is 210011111012.

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, 1610810 + ... + 6679590.

Almost surely, 2^{21011111001200} is an apocalyptic number.

21011111001200 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 21011111001200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25933733748648).

21011111001200 is an abundant number, since it is smaller than the sum of its proper divisors (30856356496096).

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

21011111001200 is a wasteful number, since it uses less digits than its factorization.

21011111001200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5069083 (or 5069072 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 21011111001200 its reverse (210011111012), we get a palindrome (21221122112212).

The spelling of 21011111001200 in words is "twenty-one trillion, eleven billion, one hundred eleven million, one thousand, two hundred".