21312102321 has 16 divisors (see below), whose sum is σ = 31711369600. Its totient is φ = 14146020144.

The previous prime is 21312102281. The next prime is 21312102337. The reversal of 21312102321 is 12320121312.

21312102321 is a `hidden beast` number, since 2 + 131 + 210 + 2 + 321 = 666.

It is not a de Polignac number, because 21312102321 - 2⁶ = 21312102257 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21312102294 and 21312102303.

It is not an unprimeable number, because it can be changed into a prime (21312102221) 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, 1717261 + ... + 1729626.

It is an arithmetic number, because the mean of its divisors is an integer number (1981960600).

Almost surely, 2^21312102321 is an apocalyptic number.

It is an amenable number.

21312102321 is a deficient number, since it is larger than the sum of its proper divisors (10399267279).

21312102321 is a wasteful number, since it uses less digits than its factorization.

21312102321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3447125 (or 3447119 counting only the distinct ones).

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

Adding to 21312102321 its reverse (12320121312), we get a palindrome (33632223633).

The spelling of 21312102321 in words is "twenty-one billion, three hundred twelve million, one hundred two thousand, three hundred twenty-one".