21110111010101 has 4 divisors (see below), whose sum is σ = 21110255145900. Its totient is φ = 21109966874304.

The previous prime is 21110111010091. The next prime is 21110111010103. The reversal of 21110111010101 is 10101011101112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 20465942644900 + 644168365201 = 4523930^2 + 802601^2 .

It is a cyclic number.

It is not a de Polignac number, because 21110111010101 - 2¹⁴ = 21110110993717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21110111010103) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71847986 + ... + 72141203.

It is an arithmetic number, because the mean of its divisors is an integer number (5277563786475).

Almost surely, 2^{21110111010101} is an apocalyptic number.

It is an amenable number.

21110111010101 is a deficient number, since it is larger than the sum of its proper divisors (144135799).

21110111010101 is a wasteful number, since it uses less digits than its factorization.

21110111010101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144135798.

The product of its (nonzero) digits is 2, while the sum is 11.

Adding to 21110111010101 its reverse (10101011101112), we get a palindrome (31211122111213).

The spelling of 21110111010101 in words is "twenty-one trillion, one hundred ten billion, one hundred eleven million, ten thousand, one hundred one".