21012120221212 has 24 divisors (see below), whose sum is σ = 39594124851120. Its totient is φ = 9720462393600.

The previous prime is 21012120221171. The next prime is 21012120221293. The reversal of 21012120221212 is 21212202121012.

It is a self number, because there is not a number n which added to its sum of digits gives 21012120221212.

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, 2618655039 + ... + 2618663062.

It is an arithmetic number, because the mean of its divisors is an integer number (1649755202130).

Almost surely, 2^{21012120221212} is an apocalyptic number.

It is an amenable number.

21012120221212 is a deficient number, since it is larger than the sum of its proper divisors (18582004629908).

21012120221212 is a wasteful number, since it uses less digits than its factorization.

21012120221212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5237318181 (or 5237318179 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21012120221212 its reverse (21212202121012), we get a palindrome (42224322342224).

The spelling of 21012120221212 in words is "twenty-one trillion, twelve billion, one hundred twenty million, two hundred twenty-one thousand, two hundred twelve".