21012121021210 has 64 divisors (see below), whose sum is σ = 41327730990720. Its totient is φ = 7628265895680.

The previous prime is 21012121021169. The next prime is 21012121021223. The reversal of 21012121021210 is 1212012121012.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 256664644 + ... + 256746496.

It is an arithmetic number, because the mean of its divisors is an integer number (645745796730).

Almost surely, 2^{21012121021210} is an apocalyptic number.

21012121021210 is a deficient number, since it is larger than the sum of its proper divisors (20315609969510).

21012121021210 is a wasteful number, since it uses less digits than its factorization.

21012121021210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85663.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21012121021210 its reverse (1212012121012), we get a palindrome (22224133142222).

The spelling of 21012121021210 in words is "twenty-one trillion, twelve billion, one hundred twenty-one million, twenty-one thousand, two hundred ten".