21011513101 has 2 divisors, whose sum is σ = 21011513102. Its totient is φ = 21011513100.

The previous prime is 21011513099. The next prime is 21011513111. The reversal of 21011513101 is 10131511012.

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., 20750690601 + 260822500 = 144051^2 + 16150^2 .

It is a cyclic number.

It is not a de Polignac number, because 21011513101 - 2¹ = 21011513099 is a prime.

Together with 21011513099, 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 (21011513111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505756550 + 10505756551.

It is an arithmetic number, because the mean of its divisors is an integer number (10505756551).

Almost surely, 2^21011513101 is an apocalyptic number.

It is an amenable number.

21011513101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011513101 is an equidigital number, since it uses as much as digits as its factorization.

21011513101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30, while the sum is 16.

The spelling of 21011513101 in words is "twenty-one billion, eleven million, five hundred thirteen thousand, one hundred one".