21212506166302 has 16 divisors (see below), whose sum is σ = 34711444987632. Its totient is φ = 9642028462720.

The previous prime is 21212506166287. The next prime is 21212506166311. The reversal of 21212506166302 is 20366160521212.

It is a congruent number.

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, 18489798 + ... + 19603510.

It is an arithmetic number, because the mean of its divisors is an integer number (2169465311727).

Almost surely, 2^{21212506166302} is an apocalyptic number.

21212506166302 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21212506166302 is a deficient number, since it is larger than the sum of its proper divisors (13498938821330).

21212506166302 is a wasteful number, since it uses less digits than its factorization.

21212506166302 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1979483.

The product of its (nonzero) digits is 51840, while the sum is 37.

Adding to 21212506166302 its reverse (20366160521212), we get a palindrome (41578666687514).

The spelling of 21212506166302 in words is "twenty-one trillion, two hundred twelve billion, five hundred six million, one hundred sixty-six thousand, three hundred two".