21100221331 has 16 divisors (see below), whose sum is σ = 25750794240. Its totient is φ = 16898948640.

The previous prime is 21100221323. The next prime is 21100221343. The reversal of 21100221331 is 13312200112.

It is not a de Polignac number, because 21100221331 - 2³ = 21100221323 is a prime.

It is a super-3 number, since 3×21100221331³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21100221301) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1670191 + ... + 1682776.

It is an arithmetic number, because the mean of its divisors is an integer number (1609424640).

Almost surely, 2^21100221331 is an apocalyptic number.

21100221331 is a deficient number, since it is larger than the sum of its proper divisors (4650572909).

21100221331 is a wasteful number, since it uses less digits than its factorization.

21100221331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3353034.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21100221331 its reverse (13312200112), we get a palindrome (34412421443).

The spelling of 21100221331 in words is "twenty-one billion, one hundred million, two hundred twenty-one thousand, three hundred thirty-one".