21211210105 has 8 divisors (see below), whose sum is σ = 25454715264. Its totient is φ = 16968126000.

The previous prime is 21211210103. The next prime is 21211210109. The reversal of 21211210105 is 50101211212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21211210105 - 2¹ = 21211210103 is a prime.

It is a super-2 number, since 2×21211210105² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21211210103) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18880 + ... + 206830.

It is an arithmetic number, because the mean of its divisors is an integer number (3181839408).

Almost surely, 2^21211210105 is an apocalyptic number.

It is an amenable number.

21211210105 is a deficient number, since it is larger than the sum of its proper divisors (4243505159).

21211210105 is a wasteful number, since it uses less digits than its factorization.

21211210105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210527.

The product of its (nonzero) digits is 40, while the sum is 16.

Adding to 21211210105 its reverse (50101211212), we get a palindrome (71312421317).

The spelling of 21211210105 in words is "twenty-one billion, two hundred eleven million, two hundred ten thousand, one hundred five".