21312312101 has 2 divisors, whose sum is σ = 21312312102. Its totient is φ = 21312312100.

The previous prime is 21312312083. The next prime is 21312312143. The reversal of 21312312101 is 10121321312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16412172100 + 4900140001 = 128110^2 + 70001^2 .

It is a cyclic number.

It is not a de Polignac number, because 21312312101 - 2⁶ = 21312312037 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21312312101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21312312001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10656156050 + 10656156051.

It is an arithmetic number, because the mean of its divisors is an integer number (10656156051).

Almost surely, 2^21312312101 is an apocalyptic number.

It is an amenable number.

21312312101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21312312101 is an equidigital number, since it uses as much as digits as its factorization.

21312312101 is an odious number, because the sum of its binary digits is odd.

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

Adding to 21312312101 its reverse (10121321312), we get a palindrome (31433633413).

The spelling of 21312312101 in words is "twenty-one billion, three hundred twelve million, three hundred twelve thousand, one hundred one".