21311012101 has 2 divisors, whose sum is σ = 21311012102. Its totient is φ = 21311012100.

The previous prime is 21311012081. The next prime is 21311012159. The reversal of 21311012101 is 10121011312.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14910852100 + 6400160001 = 122110^2 + 80001^2 .

It is a cyclic number.

It is not a de Polignac number, because 21311012101 - 2²⁹ = 20774141189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21311012501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655506050 + 10655506051.

It is an arithmetic number, because the mean of its divisors is an integer number (10655506051).

Almost surely, 2^21311012101 is an apocalyptic number.

It is an amenable number.

21311012101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21311012101 is an equidigital number, since it uses as much as digits as its factorization.

21311012101 is an evil number, because the sum of its binary digits is even.

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

Adding to 21311012101 its reverse (10121011312), we get a palindrome (31432023413).

The spelling of 21311012101 in words is "twenty-one billion, three hundred eleven million, twelve thousand, one hundred one".