21312020101 has 2 divisors, whose sum is σ = 21312020102. Its totient is φ = 21312020100.

The previous prime is 21312020099. The next prime is 21312020137. The reversal of 21312020101 is 10102021312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20808062500 + 503957601 = 144250^2 + 22449^2 .

It is a cyclic number.

It is not a de Polignac number, because 21312020101 - 2¹ = 21312020099 is a prime.

Together with 21312020099, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21312020161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10656010050 + 10656010051.

It is an arithmetic number, because the mean of its divisors is an integer number (10656010051).

Almost surely, 2^21312020101 is an apocalyptic number.

It is an amenable number.

21312020101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21312020101 is an equidigital number, since it uses as much as digits as its factorization.

21312020101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21312020101 its reverse (10102021312), we get a palindrome (31414041413).

The spelling of 21312020101 in words is "twenty-one billion, three hundred twelve million, twenty thousand, one hundred one".