21212100099 has 72 divisors (see below), whose sum is σ = 33670391040. Its totient is φ = 13325548464.

The previous prime is 21212100097. The next prime is 21212100121. The reversal of 21212100099 is 99000121212.

It is not a de Polignac number, because 21212100099 - 2¹ = 21212100097 is a prime.

It is a super-3 number, since 3×21212100099³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21212100097) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 32784994 + ... + 32785640.

It is an arithmetic number, because the mean of its divisors is an integer number (467644320).

Almost surely, 2^21212100099 is an apocalyptic number.

21212100099 is a deficient number, since it is larger than the sum of its proper divisors (12458290941).

21212100099 is an frugal number, since it uses more digits than its factorization.

21212100099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 953 (or 932 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The spelling of 21212100099 in words is "twenty-one billion, two hundred twelve million, one hundred thousand, ninety-nine".