21100210020100 has 18 divisors (see below), whose sum is σ = 45787455743834. Its totient is φ = 8440084008000.

The previous prime is 21100210020077. The next prime is 21100210020143. The reversal of 21100210020100 is 102001200112.

It can be written as a sum of positive squares in 3 ways, for example, as 4279039765056 + 16821170255044 = 2068584^2 + 4101362^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 105501050001 + ... + 105501050200.

Almost surely, 2^{21100210020100} is an apocalyptic number.

21100210020100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21100210020100 is an abundant number, since it is smaller than the sum of its proper divisors (24687245723734).

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

21100210020100 is a wasteful number, since it uses less digits than its factorization.

21100210020100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211002100215 (or 211002100208 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21100210020100 its reverse (102001200112), we get a palindrome (21202211220212).

The spelling of 21100210020100 in words is "twenty-one trillion, one hundred billion, two hundred ten million, twenty thousand, one hundred".