21212213012 has 24 divisors (see below), whose sum is σ = 39324781440. Its totient is φ = 9977189760.

The previous prime is 21212213003. The next prime is 21212213021. The reversal of 21212213012 is 21031221212.

It is an interprime number because it is at equal distance from previous prime (21212213003) and next prime (21212213021).

It is a super-2 number, since 2×21212213012² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59189 + ... + 214307.

It is an arithmetic number, because the mean of its divisors is an integer number (1638532560).

Almost surely, 2^21212213012 is an apocalyptic number.

It is an amenable number.

21212213012 is a deficient number, since it is larger than the sum of its proper divisors (18112568428).

21212213012 is a wasteful number, since it uses less digits than its factorization.

21212213012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157151 (or 157149 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21212213012 its reverse (21031221212), we get a palindrome (42243434224).

The spelling of 21212213012 in words is "twenty-one billion, two hundred twelve million, two hundred thirteen thousand, twelve".