21231213212 has 72 divisors (see below), whose sum is σ = 41566543200. Its totient is φ = 9479747200.

The previous prime is 21231213203. The next prime is 21231213217.

21231213212 is nontrivially palindromic in base 10.

It is a super-3 number, since 3×21231213212³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21231213217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10892414 + ... + 10894362.

It is an arithmetic number, because the mean of its divisors is an integer number (577313100).

Almost surely, 2^21231213212 is an apocalyptic number.

21231213212 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21231213212 is a deficient number, since it is larger than the sum of its proper divisors (20335329988).

21231213212 is a wasteful number, since it uses less digits than its factorization.

21231213212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2363 (or 2350 counting only the distinct ones).

The product of its digits is 288, while the sum is 20.

The spelling of 21231213212 in words is "twenty-one billion, two hundred thirty-one million, two hundred thirteen thousand, two hundred twelve".