21110231321 has 8 divisors (see below), whose sum is σ = 22359191400. Its totient is φ = 19862069248.

The previous prime is 21110231309. The next prime is 21110231327. The reversal of 21110231321 is 12313201112.

It can be written as a sum of positive squares in 4 ways, for example, as 17381785600 + 3728445721 = 131840^2 + 61061^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21110231321 is a prime.

It is a super-3 number, since 3×21110231321³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21110231321.

It is not an unprimeable number, because it can be changed into a prime (21110231327) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 144596 + ... + 251253.

It is an arithmetic number, because the mean of its divisors is an integer number (2794898925).

Almost surely, 2^21110231321 is an apocalyptic number.

It is an amenable number.

21110231321 is a deficient number, since it is larger than the sum of its proper divisors (1248960079).

21110231321 is a wasteful number, since it uses less digits than its factorization.

21110231321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 399003.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 21110231321 its reverse (12313201112), we get a palindrome (33423432433).

The spelling of 21110231321 in words is "twenty-one billion, one hundred ten million, two hundred thirty-one thousand, three hundred twenty-one".