21000000002100 has 288 divisors, whose sum is σ = 70149837956352. Its totient is φ = 4750963200000.

The previous prime is 21000000002099. The next prime is 21000000002203. The reversal of 21000000002100 is 120000000012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (6).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 751032120 + ... + 751060080.

Almost surely, 2^{21000000002100} is an apocalyptic number.

21000000002100 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 21000000002100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35074918978176).

21000000002100 is an abundant number, since it is smaller than the sum of its proper divisors (49149837954252).

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

21000000002100 is a wasteful number, since it uses less digits than its factorization.

21000000002100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31627 (or 31620 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 6.

Adding to 21000000002100 its reverse (120000000012), we get a palindrome (21120000002112).

It can be divided in two parts, 2100000000 and 2100, that multiplied together give a square (4410000000000 = 2100000²).

The spelling of 21000000002100 in words is "twenty-one trillion, two thousand, one hundred".