21103221321 has 96 divisors (see below), whose sum is σ = 40559850240. Its totient is φ = 10260214272.

The previous prime is 21103221317. The next prime is 21103221341. The reversal of 21103221321 is 12312230112.

21103221321 is a `hidden beast` number, since 21 + 1 + 0 + 322 + 1 + 321 = 666.

It is not a de Polignac number, because 21103221321 - 2² = 21103221317 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21103221294 and 21103221303.

It is not an unprimeable number, because it can be changed into a prime (21103221301) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 557431 + ... + 594083.

It is an arithmetic number, because the mean of its divisors is an integer number (422498440).

Almost surely, 2^21103221321 is an apocalyptic number.

21103221321 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21103221321 is a deficient number, since it is larger than the sum of its proper divisors (19456628919).

21103221321 is a wasteful number, since it uses less digits than its factorization.

21103221321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36735 (or 36732 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21103221321 its reverse (12312230112), we get a palindrome (33415451433).

The spelling of 21103221321 in words is "twenty-one billion, one hundred three million, two hundred twenty-one thousand, three hundred twenty-one".