21211210106 has 8 divisors (see below), whose sum is σ = 32252662164. Its totient is φ = 10460322720.

The previous prime is 21211210103. The next prime is 21211210109. The reversal of 21211210106 is 60101211212.

It is an interprime number because it is at equal distance from previous prime (21211210103) and next prime (21211210109).

It can be written as a sum of positive squares in 2 ways, for example, as 20921018881 + 290191225 = 144641^2 + 17035^2 .

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

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 3 ways as a sum of consecutive naturals, for example, 72640985 + ... + 72641276.

Almost surely, 2^21211210106 is an apocalyptic number.

21211210106 is a deficient number, since it is larger than the sum of its proper divisors (11041452058).

21211210106 is a wasteful number, since it uses less digits than its factorization.

21211210106 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145282336.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 21211210106 its reverse (60101211212), we get a palindrome (81312421318).

The spelling of 21211210106 in words is "twenty-one billion, two hundred eleven million, two hundred ten thousand, one hundred six".