21212121111010 has 16 divisors (see below), whose sum is σ = 38242328023872. Its totient is φ = 8471401772400.

The previous prime is 21212121110981. The next prime is 21212121111059. The reversal of 21212121111010 is 1011112121212.

It is a super-2 number, since 2×21212121111010² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1680827376 + ... + 1680839995.

It is an arithmetic number, because the mean of its divisors is an integer number (2390145501492).

Almost surely, 2^{21212121111010} is an apocalyptic number.

21212121111010 is a deficient number, since it is larger than the sum of its proper divisors (17030206912862).

21212121111010 is a wasteful number, since it uses less digits than its factorization.

21212121111010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3361668009.

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

Adding to 21212121111010 its reverse (1011112121212), we get a palindrome (22223233232222).

The spelling of 21212121111010 in words is "twenty-one trillion, two hundred twelve billion, one hundred twenty-one million, one hundred eleven thousand, ten".