21201040100 has 18 divisors (see below), whose sum is σ = 46006257234. Its totient is φ = 8480416000.

The previous prime is 21201040067. The next prime is 21201040109. The reversal of 21201040100 is 104010212.

It can be written as a sum of positive squares in 3 ways, for example, as 1599360064 + 19601680036 = 39992^2 + 140006^2 .

It is not an unprimeable number, because it can be changed into a prime (21201040109) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 106005101 + ... + 106005300.

Almost surely, 2^21201040100 is an apocalyptic number.

21201040100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21201040100 is an abundant number, since it is smaller than the sum of its proper divisors (24805217134).

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

21201040100 is a wasteful number, since it uses less digits than its factorization.

21201040100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212010415 (or 212010408 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21201040100 its reverse (104010212), we get a palindrome (21305050312).

The spelling of 21201040100 in words is "twenty-one billion, two hundred one million, forty thousand, one hundred".