21111222011100 has 72 divisors (see below), whose sum is σ = 65780402545200. Its totient is φ = 5196608494080.

The previous prime is 21111222011083. The next prime is 21111222011101. The reversal of 21111222011100 is 111022211112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21111222011100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111222011101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2706563025 + ... + 2706570824.

Almost surely, 2^{21111222011100} is an apocalyptic number.

21111222011100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21111222011100 is an abundant number, since it is smaller than the sum of its proper divisors (44669180534100).

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

21111222011100 is a wasteful number, since it uses less digits than its factorization.

21111222011100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5413133879 (or 5413133872 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21111222011100 its reverse (111022211112), we get a palindrome (21222244222212).

The spelling of 21111222011100 in words is "twenty-one trillion, one hundred eleven billion, two hundred twenty-two million, eleven thousand, one hundred".