21251112212 has 12 divisors (see below), whose sum is σ = 40570305216. Its totient is φ = 9659596440.

The previous prime is 21251112209. The next prime is 21251112221. The reversal of 21251112212 is 21221115212.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 241489868 + ... + 241489955.

It is an arithmetic number, because the mean of its divisors is an integer number (3380858768).

Almost surely, 2^21251112212 is an apocalyptic number.

21251112212 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21251112212 is a deficient number, since it is larger than the sum of its proper divisors (19319193004).

21251112212 is a wasteful number, since it uses less digits than its factorization.

21251112212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 482979838 (or 482979836 counting only the distinct ones).

The product of its digits is 160, while the sum is 20.

Adding to 21251112212 its reverse (21221115212), we get a palindrome (42472227424).

The spelling of 21251112212 in words is "twenty-one billion, two hundred fifty-one million, one hundred twelve thousand, two hundred twelve".