21110101321 has 4 divisors (see below), whose sum is σ = 21110924052. Its totient is φ = 21109278592.

The previous prime is 21110101301. The next prime is 21110101351. The reversal of 21110101321 is 12310101112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4108810000 + 17001291321 = 64100^2 + 130389^2 .

It is a cyclic number.

It is not a de Polignac number, because 21110101321 - 2²³ = 21101712713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21110101301) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 371596 + ... + 424621.

It is an arithmetic number, because the mean of its divisors is an integer number (5277731013).

Almost surely, 2^21110101321 is an apocalyptic number.

It is an amenable number.

21110101321 is a deficient number, since it is larger than the sum of its proper divisors (822731).

21110101321 is an equidigital number, since it uses as much as digits as its factorization.

21110101321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 822730.

The product of its (nonzero) digits is 12, while the sum is 13.

Adding to 21110101321 its reverse (12310101112), we get a palindrome (33420202433).

The spelling of 21110101321 in words is "twenty-one billion, one hundred ten million, one hundred one thousand, three hundred twenty-one".