21330221212 has 48 divisors (see below), whose sum is σ = 39303677952. Its totient is φ = 10114827840.

The previous prime is 21330221191. The next prime is 21330221287. The reversal of 21330221212 is 21212203312.

It is a self number, because there is not a number n which added to its sum of digits gives 21330221212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9508563 + ... + 9510805.

It is an arithmetic number, because the mean of its divisors is an integer number (818826624).

Almost surely, 2^21330221212 is an apocalyptic number.

It is an amenable number.

21330221212 is a deficient number, since it is larger than the sum of its proper divisors (17973456740).

21330221212 is a wasteful number, since it uses less digits than its factorization.

21330221212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3778 (or 3776 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21330221212 its reverse (21212203312), we get a palindrome (42542424524).

It can be divided in two parts, 213 and 30221212, that added together give a triangular number (30221425 = T₇₇₇₄).

The spelling of 21330221212 in words is "twenty-one billion, three hundred thirty million, two hundred twenty-one thousand, two hundred twelve".