21112101 has 12 divisors (see below), whose sum is σ = 30776460. Its totient is φ = 13944960.

The previous prime is 21112093. The next prime is 21112103. The reversal of 21112101 is 10121112.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 12852225 + 8259876 = 3585^2 + 2874^2 .

It is not a de Polignac number, because 21112101 - 2³ = 21112093 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112103) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9780 + ... + 11741.

It is an arithmetic number, because the mean of its divisors is an integer number (2564705).

Almost surely, 2^21112101 is an apocalyptic number.

It is an amenable number.

21112101 is a deficient number, since it is larger than the sum of its proper divisors (9664359).

21112101 is a wasteful number, since it uses less digits than its factorization.

21112101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21636 (or 21633 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

The square root of 21112101 is about 4594.7906372326. The cubic root of 21112101 is about 276.3824644027.

Adding to 21112101 its reverse (10121112), we get a palindrome (31233213).

It can be divided in two parts, 21112 and 101, that multiplied together give a palindrome (2132312).

The spelling of 21112101 in words is "twenty-one million, one hundred twelve thousand, one hundred one".